summaryrefslogtreecommitdiffstats
path: root/third_party/googletest/googlemock/include/gmock/gmock-actions.h
blob: c785ad8abba40f95cc8f0e8aef8c20e2a0f76fb0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
// Copyright 2007, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// Google Mock - a framework for writing C++ mock classes.
//
// The ACTION* family of macros can be used in a namespace scope to
// define custom actions easily.  The syntax:
//
//   ACTION(name) { statements; }
//
// will define an action with the given name that executes the
// statements.  The value returned by the statements will be used as
// the return value of the action.  Inside the statements, you can
// refer to the K-th (0-based) argument of the mock function by
// 'argK', and refer to its type by 'argK_type'.  For example:
//
//   ACTION(IncrementArg1) {
//     arg1_type temp = arg1;
//     return ++(*temp);
//   }
//
// allows you to write
//
//   ...WillOnce(IncrementArg1());
//
// You can also refer to the entire argument tuple and its type by
// 'args' and 'args_type', and refer to the mock function type and its
// return type by 'function_type' and 'return_type'.
//
// Note that you don't need to specify the types of the mock function
// arguments.  However rest assured that your code is still type-safe:
// you'll get a compiler error if *arg1 doesn't support the ++
// operator, or if the type of ++(*arg1) isn't compatible with the
// mock function's return type, for example.
//
// Sometimes you'll want to parameterize the action.   For that you can use
// another macro:
//
//   ACTION_P(name, param_name) { statements; }
//
// For example:
//
//   ACTION_P(Add, n) { return arg0 + n; }
//
// will allow you to write:
//
//   ...WillOnce(Add(5));
//
// Note that you don't need to provide the type of the parameter
// either.  If you need to reference the type of a parameter named
// 'foo', you can write 'foo_type'.  For example, in the body of
// ACTION_P(Add, n) above, you can write 'n_type' to refer to the type
// of 'n'.
//
// We also provide ACTION_P2, ACTION_P3, ..., up to ACTION_P10 to support
// multi-parameter actions.
//
// For the purpose of typing, you can view
//
//   ACTION_Pk(Foo, p1, ..., pk) { ... }
//
// as shorthand for
//
//   template <typename p1_type, ..., typename pk_type>
//   FooActionPk<p1_type, ..., pk_type> Foo(p1_type p1, ..., pk_type pk) { ... }
//
// In particular, you can provide the template type arguments
// explicitly when invoking Foo(), as in Foo<long, bool>(5, false);
// although usually you can rely on the compiler to infer the types
// for you automatically.  You can assign the result of expression
// Foo(p1, ..., pk) to a variable of type FooActionPk<p1_type, ...,
// pk_type>.  This can be useful when composing actions.
//
// You can also overload actions with different numbers of parameters:
//
//   ACTION_P(Plus, a) { ... }
//   ACTION_P2(Plus, a, b) { ... }
//
// While it's tempting to always use the ACTION* macros when defining
// a new action, you should also consider implementing ActionInterface
// or using MakePolymorphicAction() instead, especially if you need to
// use the action a lot.  While these approaches require more work,
// they give you more control on the types of the mock function
// arguments and the action parameters, which in general leads to
// better compiler error messages that pay off in the long run.  They
// also allow overloading actions based on parameter types (as opposed
// to just based on the number of parameters).
//
// CAVEAT:
//
// ACTION*() can only be used in a namespace scope as templates cannot be
// declared inside of a local class.
// Users can, however, define any local functors (e.g. a lambda) that
// can be used as actions.
//
// MORE INFORMATION:
//
// To learn more about using these macros, please search for 'ACTION' on
// https://github.com/google/googletest/blob/master/docs/gmock_cook_book.md

// IWYU pragma: private, include "gmock/gmock.h"
// IWYU pragma: friend gmock/.*

#ifndef GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_ACTIONS_H_
#define GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_ACTIONS_H_

#ifndef _WIN32_WCE
#include <errno.h>
#endif

#include <algorithm>
#include <functional>
#include <memory>
#include <string>
#include <tuple>
#include <type_traits>
#include <utility>

#include "gmock/internal/gmock-internal-utils.h"
#include "gmock/internal/gmock-port.h"
#include "gmock/internal/gmock-pp.h"

#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable : 4100)
#endif

namespace testing {

// To implement an action Foo, define:
//   1. a class FooAction that implements the ActionInterface interface, and
//   2. a factory function that creates an Action object from a
//      const FooAction*.
//
// The two-level delegation design follows that of Matcher, providing
// consistency for extension developers.  It also eases ownership
// management as Action objects can now be copied like plain values.

namespace internal {

// BuiltInDefaultValueGetter<T, true>::Get() returns a
// default-constructed T value.  BuiltInDefaultValueGetter<T,
// false>::Get() crashes with an error.
//
// This primary template is used when kDefaultConstructible is true.
template <typename T, bool kDefaultConstructible>
struct BuiltInDefaultValueGetter {
  static T Get() { return T(); }
};
template <typename T>
struct BuiltInDefaultValueGetter<T, false> {
  static T Get() {
    Assert(false, __FILE__, __LINE__,
           "Default action undefined for the function return type.");
    return internal::Invalid<T>();
    // The above statement will never be reached, but is required in
    // order for this function to compile.
  }
};

// BuiltInDefaultValue<T>::Get() returns the "built-in" default value
// for type T, which is NULL when T is a raw pointer type, 0 when T is
// a numeric type, false when T is bool, or "" when T is string or
// std::string.  In addition, in C++11 and above, it turns a
// default-constructed T value if T is default constructible.  For any
// other type T, the built-in default T value is undefined, and the
// function will abort the process.
template <typename T>
class BuiltInDefaultValue {
 public:
  // This function returns true if and only if type T has a built-in default
  // value.
  static bool Exists() { return ::std::is_default_constructible<T>::value; }

  static T Get() {
    return BuiltInDefaultValueGetter<
        T, ::std::is_default_constructible<T>::value>::Get();
  }
};

// This partial specialization says that we use the same built-in
// default value for T and const T.
template <typename T>
class BuiltInDefaultValue<const T> {
 public:
  static bool Exists() { return BuiltInDefaultValue<T>::Exists(); }
  static T Get() { return BuiltInDefaultValue<T>::Get(); }
};

// This partial specialization defines the default values for pointer
// types.
template <typename T>
class BuiltInDefaultValue<T*> {
 public:
  static bool Exists() { return true; }
  static T* Get() { return nullptr; }
};

// The following specializations define the default values for
// specific types we care about.
#define GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(type, value) \
  template <>                                                     \
  class BuiltInDefaultValue<type> {                               \
   public:                                                        \
    static bool Exists() { return true; }                         \
    static type Get() { return value; }                           \
  }

GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(void, );  // NOLINT
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(::std::string, "");
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(bool, false);
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned char, '\0');
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed char, '\0');
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(char, '\0');

// There's no need for a default action for signed wchar_t, as that
// type is the same as wchar_t for gcc, and invalid for MSVC.
//
// There's also no need for a default action for unsigned wchar_t, as
// that type is the same as unsigned int for gcc, and invalid for
// MSVC.
#if GMOCK_WCHAR_T_IS_NATIVE_
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(wchar_t, 0U);  // NOLINT
#endif

GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned short, 0U);  // NOLINT
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed short, 0);     // NOLINT
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned int, 0U);
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed int, 0);
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned long, 0UL);     // NOLINT
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed long, 0L);        // NOLINT
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned long long, 0);  // NOLINT
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed long long, 0);    // NOLINT
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(float, 0);
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(double, 0);

#undef GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_

// Partial implementations of metaprogramming types from the standard library
// not available in C++11.

template <typename P>
struct negation
    // NOLINTNEXTLINE
    : std::integral_constant<bool, bool(!P::value)> {};

// Base case: with zero predicates the answer is always true.
template <typename...>
struct conjunction : std::true_type {};

// With a single predicate, the answer is that predicate.
template <typename P1>
struct conjunction<P1> : P1 {};

// With multiple predicates the answer is the first predicate if that is false,
// and we recurse otherwise.
template <typename P1, typename... Ps>
struct conjunction<P1, Ps...>
    : std::conditional<bool(P1::value), conjunction<Ps...>, P1>::type {};

template <typename...>
struct disjunction : std::false_type {};

template <typename P1>
struct disjunction<P1> : P1 {};

template <typename P1, typename... Ps>
struct disjunction<P1, Ps...>
    // NOLINTNEXTLINE
    : std::conditional<!bool(P1::value), disjunction<Ps...>, P1>::type {};

template <typename...>
using void_t = void;

// Detects whether an expression of type `From` can be implicitly converted to
// `To` according to [conv]. In C++17, [conv]/3 defines this as follows:
//
//     An expression e can be implicitly converted to a type T if and only if
//     the declaration T t=e; is well-formed, for some invented temporary
//     variable t ([dcl.init]).
//
// [conv]/2 implies we can use function argument passing to detect whether this
// initialization is valid.
//
// Note that this is distinct from is_convertible, which requires this be valid:
//
//     To test() {
//       return declval<From>();
//     }
//
// In particular, is_convertible doesn't give the correct answer when `To` and
// `From` are the same non-moveable type since `declval<From>` will be an rvalue
// reference, defeating the guaranteed copy elision that would otherwise make
// this function work.
//
// REQUIRES: `From` is not cv void.
template <typename From, typename To>
struct is_implicitly_convertible {
 private:
  // A function that accepts a parameter of type T. This can be called with type
  // U successfully only if U is implicitly convertible to T.
  template <typename T>
  static void Accept(T);

  // A function that creates a value of type T.
  template <typename T>
  static T Make();

  // An overload be selected when implicit conversion from T to To is possible.
  template <typename T, typename = decltype(Accept<To>(Make<T>()))>
  static std::true_type TestImplicitConversion(int);

  // A fallback overload selected in all other cases.
  template <typename T>
  static std::false_type TestImplicitConversion(...);

 public:
  using type = decltype(TestImplicitConversion<From>(0));
  static constexpr bool value = type::value;
};

// Like std::invoke_result_t from C++17, but works only for objects with call
// operators (not e.g. member function pointers, which we don't need specific
// support for in OnceAction because std::function deals with them).
template <typename F, typename... Args>
using call_result_t = decltype(std::declval<F>()(std::declval<Args>()...));

template <typename Void, typename R, typename F, typename... Args>
struct is_callable_r_impl : std::false_type {};

// Specialize the struct for those template arguments where call_result_t is
// well-formed. When it's not, the generic template above is chosen, resulting
// in std::false_type.
template <typename R, typename F, typename... Args>
struct is_callable_r_impl<void_t<call_result_t<F, Args...>>, R, F, Args...>
    : std::conditional<
          std::is_void<R>::value,  //
          std::true_type,          //
          is_implicitly_convertible<call_result_t<F, Args...>, R>>::type {};

// Like std::is_invocable_r from C++17, but works only for objects with call
// operators. See the note on call_result_t.
template <typename R, typename F, typename... Args>
using is_callable_r = is_callable_r_impl<void, R, F, Args...>;

// Like std::as_const from C++17.
template <typename T>
typename std::add_const<T>::type& as_const(T& t) {
  return t;
}

}  // namespace internal

// Specialized for function types below.
template <typename F>
class OnceAction;

// An action that can only be used once.
//
// This is accepted by WillOnce, which doesn't require the underlying action to
// be copy-constructible (only move-constructible), and promises to invoke it as
// an rvalue reference. This allows the action to work with move-only types like
// std::move_only_function in a type-safe manner.
//
// For example:
//
//     // Assume we have some API that needs to accept a unique pointer to some
//     // non-copyable object Foo.
//     void AcceptUniquePointer(std::unique_ptr<Foo> foo);
//
//     // We can define an action that provides a Foo to that API. Because It
//     // has to give away its unique pointer, it must not be called more than
//     // once, so its call operator is &&-qualified.
//     struct ProvideFoo {
//       std::unique_ptr<Foo> foo;
//
//       void operator()() && {
//         AcceptUniquePointer(std::move(Foo));
//       }
//     };
//
//     // This action can be used with WillOnce.
//     EXPECT_CALL(mock, Call)
//         .WillOnce(ProvideFoo{std::make_unique<Foo>(...)});
//
//     // But a call to WillRepeatedly will fail to compile. This is correct,
//     // since the action cannot correctly be used repeatedly.
//     EXPECT_CALL(mock, Call)
//         .WillRepeatedly(ProvideFoo{std::make_unique<Foo>(...)});
//
// A less-contrived example would be an action that returns an arbitrary type,
// whose &&-qualified call operator is capable of dealing with move-only types.
template <typename Result, typename... Args>
class OnceAction<Result(Args...)> final {
 private:
  // True iff we can use the given callable type (or lvalue reference) directly
  // via StdFunctionAdaptor.
  template <typename Callable>
  using IsDirectlyCompatible = internal::conjunction<
      // It must be possible to capture the callable in StdFunctionAdaptor.
      std::is_constructible<typename std::decay<Callable>::type, Callable>,
      // The callable must be compatible with our signature.
      internal::is_callable_r<Result, typename std::decay<Callable>::type,
                              Args...>>;

  // True iff we can use the given callable type via StdFunctionAdaptor once we
  // ignore incoming arguments.
  template <typename Callable>
  using IsCompatibleAfterIgnoringArguments = internal::conjunction<
      // It must be possible to capture the callable in a lambda.
      std::is_constructible<typename std::decay<Callable>::type, Callable>,
      // The callable must be invocable with zero arguments, returning something
      // convertible to Result.
      internal::is_callable_r<Result, typename std::decay<Callable>::type>>;

 public:
  // Construct from a callable that is directly compatible with our mocked
  // signature: it accepts our function type's arguments and returns something
  // convertible to our result type.
  template <typename Callable,
            typename std::enable_if<
                internal::conjunction<
                    // Teach clang on macOS that we're not talking about a
                    // copy/move constructor here. Otherwise it gets confused
                    // when checking the is_constructible requirement of our
                    // traits above.
                    internal::negation<std::is_same<
                        OnceAction, typename std::decay<Callable>::type>>,
                    IsDirectlyCompatible<Callable>>  //
                ::value,
                int>::type = 0>
  OnceAction(Callable&& callable)  // NOLINT
      : function_(StdFunctionAdaptor<typename std::decay<Callable>::type>(
            {}, std::forward<Callable>(callable))) {}

  // As above, but for a callable that ignores the mocked function's arguments.
  template <typename Callable,
            typename std::enable_if<
                internal::conjunction<
                    // Teach clang on macOS that we're not talking about a
                    // copy/move constructor here. Otherwise it gets confused
                    // when checking the is_constructible requirement of our
                    // traits above.
                    internal::negation<std::is_same<
                        OnceAction, typename std::decay<Callable>::type>>,
                    // Exclude callables for which the overload above works.
                    // We'd rather provide the arguments if possible.
                    internal::negation<IsDirectlyCompatible<Callable>>,
                    IsCompatibleAfterIgnoringArguments<Callable>>::value,
                int>::type = 0>
  OnceAction(Callable&& callable)  // NOLINT
                                   // Call the constructor above with a callable
                                   // that ignores the input arguments.
      : OnceAction(IgnoreIncomingArguments<typename std::decay<Callable>::type>{
            std::forward<Callable>(callable)}) {}

  // We are naturally copyable because we store only an std::function, but
  // semantically we should not be copyable.
  OnceAction(const OnceAction&) = delete;
  OnceAction& operator=(const OnceAction&) = delete;
  OnceAction(OnceAction&&) = default;

  // Invoke the underlying action callable with which we were constructed,
  // handing it the supplied arguments.
  Result Call(Args... args) && {
    return function_(std::forward<Args>(args)...);
  }

 private:
  // An adaptor that wraps a callable that is compatible with our signature and
  // being invoked as an rvalue reference so that it can be used as an
  // StdFunctionAdaptor. This throws away type safety, but that's fine because
  // this is only used by WillOnce, which we know calls at most once.
  //
  // Once we have something like std::move_only_function from C++23, we can do
  // away with this.
  template <typename Callable>
  class StdFunctionAdaptor final {
   public:
    // A tag indicating that the (otherwise universal) constructor is accepting
    // the callable itself, instead of e.g. stealing calls for the move
    // constructor.
    struct CallableTag final {};

    template <typename F>
    explicit StdFunctionAdaptor(CallableTag, F&& callable)
        : callable_(std::make_shared<Callable>(std::forward<F>(callable))) {}

    // Rather than explicitly returning Result, we return whatever the wrapped
    // callable returns. This allows for compatibility with existing uses like
    // the following, when the mocked function returns void:
    //
    //     EXPECT_CALL(mock_fn_, Call)
    //         .WillOnce([&] {
    //            [...]
    //            return 0;
    //         });
    //
    // Such a callable can be turned into std::function<void()>. If we use an
    // explicit return type of Result here then it *doesn't* work with
    // std::function, because we'll get a "void function should not return a
    // value" error.
    //
    // We need not worry about incompatible result types because the SFINAE on
    // OnceAction already checks this for us. std::is_invocable_r_v itself makes
    // the same allowance for void result types.
    template <typename... ArgRefs>
    internal::call_result_t<Callable, ArgRefs...> operator()(
        ArgRefs&&... args) const {
      return std::move(*callable_)(std::forward<ArgRefs>(args)...);
    }

   private:
    // We must put the callable on the heap so that we are copyable, which
    // std::function needs.
    std::shared_ptr<Callable> callable_;
  };

  // An adaptor that makes a callable that accepts zero arguments callable with
  // our mocked arguments.
  template <typename Callable>
  struct IgnoreIncomingArguments {
    internal::call_result_t<Callable> operator()(Args&&...) {
      return std::move(callable)();
    }

    Callable callable;
  };

  std::function<Result(Args...)> function_;
};

// When an unexpected function call is encountered, Google Mock will
// let it return a default value if the user has specified one for its
// return type, or if the return type has a built-in default value;
// otherwise Google Mock won't know what value to return and will have
// to abort the process.
//
// The DefaultValue<T> class allows a user to specify the
// default value for a type T that is both copyable and publicly
// destructible (i.e. anything that can be used as a function return
// type).  The usage is:
//
//   // Sets the default value for type T to be foo.
//   DefaultValue<T>::Set(foo);
template <typename T>
class DefaultValue {
 public:
  // Sets the default value for type T; requires T to be
  // copy-constructable and have a public destructor.
  static void Set(T x) {
    delete producer_;
    producer_ = new FixedValueProducer(x);
  }

  // Provides a factory function to be called to generate the default value.
  // This method can be used even if T is only move-constructible, but it is not
  // limited to that case.
  typedef T (*FactoryFunction)();
  static void SetFactory(FactoryFunction factory) {
    delete producer_;
    producer_ = new FactoryValueProducer(factory);
  }

  // Unsets the default value for type T.
  static void Clear() {
    delete producer_;
    producer_ = nullptr;
  }

  // Returns true if and only if the user has set the default value for type T.
  static bool IsSet() { return producer_ != nullptr; }

  // Returns true if T has a default return value set by the user or there
  // exists a built-in default value.
  static bool Exists() {
    return IsSet() || internal::BuiltInDefaultValue<T>::Exists();
  }

  // Returns the default value for type T if the user has set one;
  // otherwise returns the built-in default value. Requires that Exists()
  // is true, which ensures that the return value is well-defined.
  static T Get() {
    return producer_ == nullptr ? internal::BuiltInDefaultValue<T>::Get()
                                : producer_->Produce();
  }

 private:
  class ValueProducer {
   public:
    virtual ~ValueProducer() {}
    virtual T Produce() = 0;
  };

  class FixedValueProducer : public ValueProducer {
   public:
    explicit FixedValueProducer(T value) : value_(value) {}
    T Produce() override { return value_; }

   private:
    const T value_;
    FixedValueProducer(const FixedValueProducer&) = delete;
    FixedValueProducer& operator=(const FixedValueProducer&) = delete;
  };

  class FactoryValueProducer : public ValueProducer {
   public:
    explicit FactoryValueProducer(FactoryFunction factory)
        : factory_(factory) {}
    T Produce() override { return factory_(); }

   private:
    const FactoryFunction factory_;
    FactoryValueProducer(const FactoryValueProducer&) = delete;
    FactoryValueProducer& operator=(const FactoryValueProducer&) = delete;
  };

  static ValueProducer* producer_;
};

// This partial specialization allows a user to set default values for
// reference types.
template <typename T>
class DefaultValue<T&> {
 public:
  // Sets the default value for type T&.
  static void Set(T& x) {  // NOLINT
    address_ = &x;
  }

  // Unsets the default value for type T&.
  static void Clear() { address_ = nullptr; }

  // Returns true if and only if the user has set the default value for type T&.
  static bool IsSet() { return address_ != nullptr; }

  // Returns true if T has a default return value set by the user or there
  // exists a built-in default value.
  static bool Exists() {
    return IsSet() || internal::BuiltInDefaultValue<T&>::Exists();
  }

  // Returns the default value for type T& if the user has set one;
  // otherwise returns the built-in default value if there is one;
  // otherwise aborts the process.
  static T& Get() {
    return address_ == nullptr ? internal::BuiltInDefaultValue<T&>::Get()
                               : *address_;
  }

 private:
  static T* address_;
};

// This specialization allows DefaultValue<void>::Get() to
// compile.
template <>
class DefaultValue<void> {
 public:
  static bool Exists() { return true; }
  static void Get() {}
};

// Points to the user-set default value for type T.
template <typename T>
typename DefaultValue<T>::ValueProducer* DefaultValue<T>::producer_ = nullptr;

// Points to the user-set default value for type T&.
template <typename T>
T* DefaultValue<T&>::address_ = nullptr;

// Implement this interface to define an action for function type F.
template <typename F>
class ActionInterface {
 public:
  typedef typename internal::Function<F>::Result Result;
  typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;

  ActionInterface() {}
  virtual ~ActionInterface() {}

  // Performs the action.  This method is not const, as in general an
  // action can have side effects and be stateful.  For example, a
  // get-the-next-element-from-the-collection action will need to
  // remember the current element.
  virtual Result Perform(const ArgumentTuple& args) = 0;

 private:
  ActionInterface(const ActionInterface&) = delete;
  ActionInterface& operator=(const ActionInterface&) = delete;
};

template <typename F>
class Action;

// An Action<R(Args...)> is a copyable and IMMUTABLE (except by assignment)
// object that represents an action to be taken when a mock function of type
// R(Args...) is called. The implementation of Action<T> is just a
// std::shared_ptr to const ActionInterface<T>. Don't inherit from Action! You
// can view an object implementing ActionInterface<F> as a concrete action
// (including its current state), and an Action<F> object as a handle to it.
template <typename R, typename... Args>
class Action<R(Args...)> {
 private:
  using F = R(Args...);

  // Adapter class to allow constructing Action from a legacy ActionInterface.
  // New code should create Actions from functors instead.
  struct ActionAdapter {
    // Adapter must be copyable to satisfy std::function requirements.
    ::std::shared_ptr<ActionInterface<F>> impl_;

    template <typename... InArgs>
    typename internal::Function<F>::Result operator()(InArgs&&... args) {
      return impl_->Perform(
          ::std::forward_as_tuple(::std::forward<InArgs>(args)...));
    }
  };

  template <typename G>
  using IsCompatibleFunctor = std::is_constructible<std::function<F>, G>;

 public:
  typedef typename internal::Function<F>::Result Result;
  typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;

  // Constructs a null Action.  Needed for storing Action objects in
  // STL containers.
  Action() {}

  // Construct an Action from a specified callable.
  // This cannot take std::function directly, because then Action would not be
  // directly constructible from lambda (it would require two conversions).
  template <
      typename G,
      typename = typename std::enable_if<internal::disjunction<
          IsCompatibleFunctor<G>, std::is_constructible<std::function<Result()>,
                                                        G>>::value>::type>
  Action(G&& fun) {  // NOLINT
    Init(::std::forward<G>(fun), IsCompatibleFunctor<G>());
  }

  // Constructs an Action from its implementation.
  explicit Action(ActionInterface<F>* impl)
      : fun_(ActionAdapter{::std::shared_ptr<ActionInterface<F>>(impl)}) {}

  // This constructor allows us to turn an Action<Func> object into an
  // Action<F>, as long as F's arguments can be implicitly converted
  // to Func's and Func's return type can be implicitly converted to F's.
  template <typename Func>
  Action(const Action<Func>& action)  // NOLINT
      : fun_(action.fun_) {}

  // Returns true if and only if this is the DoDefault() action.
  bool IsDoDefault() const { return fun_ == nullptr; }

  // Performs the action.  Note that this method is const even though
  // the corresponding method in ActionInterface is not.  The reason
  // is that a const Action<F> means that it cannot be re-bound to
  // another concrete action, not that the concrete action it binds to
  // cannot change state.  (Think of the difference between a const
  // pointer and a pointer to const.)
  Result Perform(ArgumentTuple args) const {
    if (IsDoDefault()) {
      internal::IllegalDoDefault(__FILE__, __LINE__);
    }
    return internal::Apply(fun_, ::std::move(args));
  }

  // An action can be used as a OnceAction, since it's obviously safe to call it
  // once.
  operator OnceAction<F>() const {  // NOLINT
    // Return a OnceAction-compatible callable that calls Perform with the
    // arguments it is provided. We could instead just return fun_, but then
    // we'd need to handle the IsDoDefault() case separately.
    struct OA {
      Action<F> action;

      R operator()(Args... args) && {
        return action.Perform(
            std::forward_as_tuple(std::forward<Args>(args)...));
      }
    };

    return OA{*this};
  }

 private:
  template <typename G>
  friend class Action;

  template <typename G>
  void Init(G&& g, ::std::true_type) {
    fun_ = ::std::forward<G>(g);
  }

  template <typename G>
  void Init(G&& g, ::std::false_type) {
    fun_ = IgnoreArgs<typename ::std::decay<G>::type>{::std::forward<G>(g)};
  }

  template <typename FunctionImpl>
  struct IgnoreArgs {
    template <typename... InArgs>
    Result operator()(const InArgs&...) const {
      return function_impl();
    }

    FunctionImpl function_impl;
  };

  // fun_ is an empty function if and only if this is the DoDefault() action.
  ::std::function<F> fun_;
};

// The PolymorphicAction class template makes it easy to implement a
// polymorphic action (i.e. an action that can be used in mock
// functions of than one type, e.g. Return()).
//
// To define a polymorphic action, a user first provides a COPYABLE
// implementation class that has a Perform() method template:
//
//   class FooAction {
//    public:
//     template <typename Result, typename ArgumentTuple>
//     Result Perform(const ArgumentTuple& args) const {
//       // Processes the arguments and returns a result, using
//       // std::get<N>(args) to get the N-th (0-based) argument in the tuple.
//     }
//     ...
//   };
//
// Then the user creates the polymorphic action using
// MakePolymorphicAction(object) where object has type FooAction.  See
// the definition of Return(void) and SetArgumentPointee<N>(value) for
// complete examples.
template <typename Impl>
class PolymorphicAction {
 public:
  explicit PolymorphicAction(const Impl& impl) : impl_(impl) {}

  template <typename F>
  operator Action<F>() const {
    return Action<F>(new MonomorphicImpl<F>(impl_));
  }

 private:
  template <typename F>
  class MonomorphicImpl : public ActionInterface<F> {
   public:
    typedef typename internal::Function<F>::Result Result;
    typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;

    explicit MonomorphicImpl(const Impl& impl) : impl_(impl) {}

    Result Perform(const ArgumentTuple& args) override {
      return impl_.template Perform<Result>(args);
    }

   private:
    Impl impl_;
  };

  Impl impl_;
};

// Creates an Action from its implementation and returns it.  The
// created Action object owns the implementation.
template <typename F>
Action<F> MakeAction(ActionInterface<F>* impl) {
  return Action<F>(impl);
}

// Creates a polymorphic action from its implementation.  This is
// easier to use than the PolymorphicAction<Impl> constructor as it
// doesn't require you to explicitly write the template argument, e.g.
//
//   MakePolymorphicAction(foo);
// vs
//   PolymorphicAction<TypeOfFoo>(foo);
template <typename Impl>
inline PolymorphicAction<Impl> MakePolymorphicAction(const Impl& impl) {
  return PolymorphicAction<Impl>(impl);
}

namespace internal {

// Helper struct to specialize ReturnAction to execute a move instead of a copy
// on return. Useful for move-only types, but could be used on any type.
template <typename T>
struct ByMoveWrapper {
  explicit ByMoveWrapper(T value) : payload(std::move(value)) {}
  T payload;
};

// The general implementation of Return(R). Specializations follow below.
template <typename R>
class ReturnAction final {
 public:
  explicit ReturnAction(R value) : value_(std::move(value)) {}

  template <typename U, typename... Args,
            typename = typename std::enable_if<conjunction<
                // See the requirements documented on Return.
                negation<std::is_same<void, U>>,  //
                negation<std::is_reference<U>>,   //
                std::is_convertible<R, U>,        //
                std::is_move_constructible<U>>::value>::type>
  operator OnceAction<U(Args...)>() && {  // NOLINT
    return Impl<U>(std::move(value_));
  }

  template <typename U, typename... Args,
            typename = typename std::enable_if<conjunction<
                // See the requirements documented on Return.
                negation<std::is_same<void, U>>,   //
                negation<std::is_reference<U>>,    //
                std::is_convertible<const R&, U>,  //
                std::is_copy_constructible<U>>::value>::type>
  operator Action<U(Args...)>() const {  // NOLINT
    return Impl<U>(value_);
  }

 private:
  // Implements the Return(x) action for a mock function that returns type U.
  template <typename U>
  class Impl final {
   public:
    // The constructor used when the return value is allowed to move from the
    // input value (i.e. we are converting to OnceAction).
    explicit Impl(R&& input_value)
        : state_(new State(std::move(input_value))) {}

    // The constructor used when the return value is not allowed to move from
    // the input value (i.e. we are converting to Action).
    explicit Impl(const R& input_value) : state_(new State(input_value)) {}

    U operator()() && { return std::move(state_->value); }
    U operator()() const& { return state_->value; }

   private:
    // We put our state on the heap so that the compiler-generated copy/move
    // constructors work correctly even when U is a reference-like type. This is
    // necessary only because we eagerly create State::value (see the note on
    // that symbol for details). If we instead had only the input value as a
    // member then the default constructors would work fine.
    //
    // For example, when R is std::string and U is std::string_view, value is a
    // reference to the string backed by input_value. The copy constructor would
    // copy both, so that we wind up with a new input_value object (with the
    // same contents) and a reference to the *old* input_value object rather
    // than the new one.
    struct State {
      explicit State(const R& input_value_in)
          : input_value(input_value_in),
            // Make an implicit conversion to Result before initializing the U
            // object we store, avoiding calling any explicit constructor of U
            // from R.
            //
            // This simulates the language rules: a function with return type U
            // that does `return R()` requires R to be implicitly convertible to
            // U, and uses that path for the conversion, even U Result has an
            // explicit constructor from R.
            value(ImplicitCast_<U>(internal::as_const(input_value))) {}

      // As above, but for the case where we're moving from the ReturnAction
      // object because it's being used as a OnceAction.
      explicit State(R&& input_value_in)
          : input_value(std::move(input_value_in)),
            // For the same reason as above we make an implicit conversion to U
            // before initializing the value.
            //
            // Unlike above we provide the input value as an rvalue to the
            // implicit conversion because this is a OnceAction: it's fine if it
            // wants to consume the input value.
            value(ImplicitCast_<U>(std::move(input_value))) {}

      // A copy of the value originally provided by the user. We retain this in
      // addition to the value of the mock function's result type below in case
      // the latter is a reference-like type. See the std::string_view example
      // in the documentation on Return.
      R input_value;

      // The value we actually return, as the type returned by the mock function
      // itself.
      //
      // We eagerly initialize this here, rather than lazily doing the implicit
      // conversion automatically each time Perform is called, for historical
      // reasons: in 2009-11, commit a070cbd91c (Google changelist 13540126)
      // made the Action<U()> conversion operator eagerly convert the R value to
      // U, but without keeping the R alive. This broke the use case discussed
      // in the documentation for Return, making reference-like types such as
      // std::string_view not safe to use as U where the input type R is a
      // value-like type such as std::string.
      //
      // The example the commit gave was not very clear, nor was the issue
      // thread (https://github.com/google/googlemock/issues/86), but it seems
      // the worry was about reference-like input types R that flatten to a
      // value-like type U when being implicitly converted. An example of this
      // is std::vector<bool>::reference, which is often a proxy type with an
      // reference to the underlying vector:
      //
      //     // Helper method: have the mock function return bools according
      //     // to the supplied script.
      //     void SetActions(MockFunction<bool(size_t)>& mock,
      //                     const std::vector<bool>& script) {
      //       for (size_t i = 0; i < script.size(); ++i) {
      //         EXPECT_CALL(mock, Call(i)).WillOnce(Return(script[i]));
      //       }
      //     }
      //
      //     TEST(Foo, Bar) {
      //       // Set actions using a temporary vector, whose operator[]
      //       // returns proxy objects that references that will be
      //       // dangling once the call to SetActions finishes and the
      //       // vector is destroyed.
      //       MockFunction<bool(size_t)> mock;
      //       SetActions(mock, {false, true});
      //
      //       EXPECT_FALSE(mock.AsStdFunction()(0));
      //       EXPECT_TRUE(mock.AsStdFunction()(1));
      //     }
      //
      // This eager conversion helps with a simple case like this, but doesn't
      // fully make these types work in general. For example the following still
      // uses a dangling reference:
      //
      //     TEST(Foo, Baz) {
      //       MockFunction<std::vector<std::string>()> mock;
      //
      //       // Return the same vector twice, and then the empty vector
      //       // thereafter.
      //       auto action = Return(std::initializer_list<std::string>{
      //           "taco", "burrito",
      //       });
      //
      //       EXPECT_CALL(mock, Call)
      //           .WillOnce(action)
      //           .WillOnce(action)
      //           .WillRepeatedly(Return(std::vector<std::string>{}));
      //
      //       EXPECT_THAT(mock.AsStdFunction()(),
      //                   ElementsAre("taco", "burrito"));
      //       EXPECT_THAT(mock.AsStdFunction()(),
      //                   ElementsAre("taco", "burrito"));
      //       EXPECT_THAT(mock.AsStdFunction()(), IsEmpty());
      //     }
      //
      U value;
    };

    const std::shared_ptr<State> state_;
  };

  R value_;
};

// A specialization of ReturnAction<R> when R is ByMoveWrapper<T> for some T.
//
// This version applies the type system-defeating hack of moving from T even in
// the const call operator, checking at runtime that it isn't called more than
// once, since the user has declared their intent to do so by using ByMove.
template <typename T>
class ReturnAction<ByMoveWrapper<T>> final {
 public:
  explicit ReturnAction(ByMoveWrapper<T> wrapper)
      : state_(new State(std::move(wrapper.payload))) {}

  T operator()() const {
    GTEST_CHECK_(!state_->called)
        << "A ByMove() action must be performed at most once.";

    state_->called = true;
    return std::move(state_->value);
  }

 private:
  // We store our state on the heap so that we are copyable as required by
  // Action, despite the fact that we are stateful and T may not be copyable.
  struct State {
    explicit State(T&& value_in) : value(std::move(value_in)) {}

    T value;
    bool called = false;
  };

  const std::shared_ptr<State> state_;
};

// Implements the ReturnNull() action.
class ReturnNullAction {
 public:
  // Allows ReturnNull() to be used in any pointer-returning function. In C++11
  // this is enforced by returning nullptr, and in non-C++11 by asserting a
  // pointer type on compile time.
  template <typename Result, typename ArgumentTuple>
  static Result Perform(const ArgumentTuple&) {
    return nullptr;
  }
};

// Implements the Return() action.
class ReturnVoidAction {
 public:
  // Allows Return() to be used in any void-returning function.
  template <typename Result, typename ArgumentTuple>
  static void Perform(const ArgumentTuple&) {
    static_assert(std::is_void<Result>::value, "Result should be void.");
  }
};

// Implements the polymorphic ReturnRef(x) action, which can be used
// in any function that returns a reference to the type of x,
// regardless of the argument types.
template <typename T>
class ReturnRefAction {
 public:
  // Constructs a ReturnRefAction object from the reference to be returned.
  explicit ReturnRefAction(T& ref) : ref_(ref) {}  // NOLINT

  // This template type conversion operator allows ReturnRef(x) to be
  // used in ANY function that returns a reference to x's type.
  template <typename F>
  operator Action<F>() const {
    typedef typename Function<F>::Result Result;
    // Asserts that the function return type is a reference.  This
    // catches the user error of using ReturnRef(x) when Return(x)
    // should be used, and generates some helpful error message.
    static_assert(std::is_reference<Result>::value,
                  "use Return instead of ReturnRef to return a value");
    return Action<F>(new Impl<F>(ref_));
  }

 private:
  // Implements the ReturnRef(x) action for a particular function type F.
  template <typename F>
  class Impl : public ActionInterface<F> {
   public:
    typedef typename Function<F>::Result Result;
    typedef typename Function<F>::ArgumentTuple ArgumentTuple;

    explicit Impl(T& ref) : ref_(ref) {}  // NOLINT

    Result Perform(const ArgumentTuple&) override { return ref_; }

   private:
    T& ref_;
  };

  T& ref_;
};

// Implements the polymorphic ReturnRefOfCopy(x) action, which can be
// used in any function that returns a reference to the type of x,
// regardless of the argument types.
template <typename T>
class ReturnRefOfCopyAction {
 public:
  // Constructs a ReturnRefOfCopyAction object from the reference to
  // be returned.
  explicit ReturnRefOfCopyAction(const T& value) : value_(value) {}  // NOLINT

  // This template type conversion operator allows ReturnRefOfCopy(x) to be
  // used in ANY function that returns a reference to x's type.
  template <typename F>
  operator Action<F>() const {
    typedef typename Function<F>::Result Result;
    // Asserts that the function return type is a reference.  This
    // catches the user error of using ReturnRefOfCopy(x) when Return(x)
    // should be used, and generates some helpful error message.
    static_assert(std::is_reference<Result>::value,
                  "use Return instead of ReturnRefOfCopy to return a value");
    return Action<F>(new Impl<F>(value_));
  }

 private:
  // Implements the ReturnRefOfCopy(x) action for a particular function type F.
  template <typename F>
  class Impl : public ActionInterface<F> {
   public:
    typedef typename Function<F>::Result Result;
    typedef typename Function<F>::ArgumentTuple ArgumentTuple;

    explicit Impl(const T& value) : value_(value) {}  // NOLINT

    Result Perform(const ArgumentTuple&) override { return value_; }

   private:
    T value_;
  };

  const T value_;
};

// Implements the polymorphic ReturnRoundRobin(v) action, which can be
// used in any function that returns the element_type of v.
template <typename T>
class ReturnRoundRobinAction {
 public:
  explicit ReturnRoundRobinAction(std::vector<T> values) {
    GTEST_CHECK_(!values.empty())
        << "ReturnRoundRobin requires at least one element.";
    state_->values = std::move(values);
  }

  template <typename... Args>
  T operator()(Args&&...) const {
    return state_->Next();
  }

 private:
  struct State {
    T Next() {
      T ret_val = values[i++];
      if (i == values.size()) i = 0;
      return ret_val;
    }

    std::vector<T> values;
    size_t i = 0;
  };
  std::shared_ptr<State> state_ = std::make_shared<State>();
};

// Implements the polymorphic DoDefault() action.
class DoDefaultAction {
 public:
  // This template type conversion operator allows DoDefault() to be
  // used in any function.
  template <typename F>
  operator Action<F>() const {
    return Action<F>();
  }  // NOLINT
};

// Implements the Assign action to set a given pointer referent to a
// particular value.
template <typename T1, typename T2>
class AssignAction {
 public:
  AssignAction(T1* ptr, T2 value) : ptr_(ptr), value_(value) {}

  template <typename Result, typename ArgumentTuple>
  void Perform(const ArgumentTuple& /* args */) const {
    *ptr_ = value_;
  }

 private:
  T1* const ptr_;
  const T2 value_;
};

#if !GTEST_OS_WINDOWS_MOBILE

// Implements the SetErrnoAndReturn action to simulate return from
// various system calls and libc functions.
template <typename T>
class SetErrnoAndReturnAction {
 public:
  SetErrnoAndReturnAction(int errno_value, T result)
      : errno_(errno_value), result_(result) {}
  template <typename Result, typename ArgumentTuple>
  Result Perform(const ArgumentTuple& /* args */) const {
    errno = errno_;
    return result_;
  }

 private:
  const int errno_;
  const T result_;
};

#endif  // !GTEST_OS_WINDOWS_MOBILE

// Implements the SetArgumentPointee<N>(x) action for any function
// whose N-th argument (0-based) is a pointer to x's type.
template <size_t N, typename A, typename = void>
struct SetArgumentPointeeAction {
  A value;

  template <typename... Args>
  void operator()(const Args&... args) const {
    *::std::get<N>(std::tie(args...)) = value;
  }
};

// Implements the Invoke(object_ptr, &Class::Method) action.
template <class Class, typename MethodPtr>
struct InvokeMethodAction {
  Class* const obj_ptr;
  const MethodPtr method_ptr;

  template <typename... Args>
  auto operator()(Args&&... args) const
      -> decltype((obj_ptr->*method_ptr)(std::forward<Args>(args)...)) {
    return (obj_ptr->*method_ptr)(std::forward<Args>(args)...);
  }
};

// Implements the InvokeWithoutArgs(f) action.  The template argument
// FunctionImpl is the implementation type of f, which can be either a
// function pointer or a functor.  InvokeWithoutArgs(f) can be used as an
// Action<F> as long as f's type is compatible with F.
template <typename FunctionImpl>
struct InvokeWithoutArgsAction {
  FunctionImpl function_impl;

  // Allows InvokeWithoutArgs(f) to be used as any action whose type is
  // compatible with f.
  template <typename... Args>
  auto operator()(const Args&...) -> decltype(function_impl()) {
    return function_impl();
  }
};

// Implements the InvokeWithoutArgs(object_ptr, &Class::Method) action.
template <class Class, typename MethodPtr>
struct InvokeMethodWithoutArgsAction {
  Class* const obj_ptr;
  const MethodPtr method_ptr;

  using ReturnType =
      decltype((std::declval<Class*>()->*std::declval<MethodPtr>())());

  template <typename... Args>
  ReturnType operator()(const Args&...) const {
    return (obj_ptr->*method_ptr)();
  }
};

// Implements the IgnoreResult(action) action.
template <typename A>
class IgnoreResultAction {
 public:
  explicit IgnoreResultAction(const A& action) : action_(action) {}

  template <typename F>
  operator Action<F>() const {
    // Assert statement belongs here because this is the best place to verify
    // conditions on F. It produces the clearest error messages
    // in most compilers.
    // Impl really belongs in this scope as a local class but can't
    // because MSVC produces duplicate symbols in different translation units
    // in this case. Until MS fixes that bug we put Impl into the class scope
    // and put the typedef both here (for use in assert statement) and
    // in the Impl class. But both definitions must be the same.
    typedef typename internal::Function<F>::Result Result;

    // Asserts at compile time that F returns void.
    static_assert(std::is_void<Result>::value, "Result type should be void.");

    return Action<F>(new Impl<F>(action_));
  }

 private:
  template <typename F>
  class Impl : public ActionInterface<F> {
   public:
    typedef typename internal::Function<F>::Result Result;
    typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;

    explicit Impl(const A& action) : action_(action) {}

    void Perform(const ArgumentTuple& args) override {
      // Performs the action and ignores its result.
      action_.Perform(args);
    }

   private:
    // Type OriginalFunction is the same as F except that its return
    // type is IgnoredValue.
    typedef
        typename internal::Function<F>::MakeResultIgnoredValue OriginalFunction;

    const Action<OriginalFunction> action_;
  };

  const A action_;
};

template <typename InnerAction, size_t... I>
struct WithArgsAction {
  InnerAction inner_action;

  // The signature of the function as seen by the inner action, given an out
  // action with the given result and argument types.
  template <typename R, typename... Args>
  using InnerSignature =
      R(typename std::tuple_element<I, std::tuple<Args...>>::type...);

  // Rather than a call operator, we must define conversion operators to
  // particular action types. This is necessary for embedded actions like
  // DoDefault(), which rely on an action conversion operators rather than
  // providing a call operator because even with a particular set of arguments
  // they don't have a fixed return type.

  template <typename R, typename... Args,
            typename std::enable_if<
                std::is_convertible<
                    InnerAction,
                    // Unfortunately we can't use the InnerSignature alias here;
                    // MSVC complains about the I parameter pack not being
                    // expanded (error C3520) despite it being expanded in the
                    // type alias.
                    OnceAction<R(typename std::tuple_element<
                                 I, std::tuple<Args...>>::type...)>>::value,
                int>::type = 0>
  operator OnceAction<R(Args...)>() && {  // NOLINT
    struct OA {
      OnceAction<InnerSignature<R, Args...>> inner_action;

      R operator()(Args&&... args) && {
        return std::move(inner_action)
            .Call(std::get<I>(
                std::forward_as_tuple(std::forward<Args>(args)...))...);
      }
    };

    return OA{std::move(inner_action)};
  }

  template <typename R, typename... Args,
            typename std::enable_if<
                std::is_convertible<
                    const InnerAction&,
                    // Unfortunately we can't use the InnerSignature alias here;
                    // MSVC complains about the I parameter pack not being
                    // expanded (error C3520) despite it being expanded in the
                    // type alias.
                    Action<R(typename std::tuple_element<
                             I, std::tuple<Args...>>::type...)>>::value,
                int>::type = 0>
  operator Action<R(Args...)>() const {  // NOLINT
    Action<InnerSignature<R, Args...>> converted(inner_action);

    return [converted](Args&&... args) -> R {
      return converted.Perform(std::forward_as_tuple(
          std::get<I>(std::forward_as_tuple(std::forward<Args>(args)...))...));
    };
  }
};

template <typename... Actions>
class DoAllAction;

// Base case: only a single action.
template <typename FinalAction>
class DoAllAction<FinalAction> {
 public:
  struct UserConstructorTag {};

  template <typename T>
  explicit DoAllAction(UserConstructorTag, T&& action)
      : final_action_(std::forward<T>(action)) {}

  // Rather than a call operator, we must define conversion operators to
  // particular action types. This is necessary for embedded actions like
  // DoDefault(), which rely on an action conversion operators rather than
  // providing a call operator because even with a particular set of arguments
  // they don't have a fixed return type.

  template <typename R, typename... Args,
            typename std::enable_if<
                std::is_convertible<FinalAction, OnceAction<R(Args...)>>::value,
                int>::type = 0>
  operator OnceAction<R(Args...)>() && {  // NOLINT
    return std::move(final_action_);
  }

  template <
      typename R, typename... Args,
      typename std::enable_if<
          std::is_convertible<const FinalAction&, Action<R(Args...)>>::value,
          int>::type = 0>
  operator Action<R(Args...)>() const {  // NOLINT
    return final_action_;
  }

 private:
  FinalAction final_action_;
};

// Recursive case: support N actions by calling the initial action and then
// calling through to the base class containing N-1 actions.
template <typename InitialAction, typename... OtherActions>
class DoAllAction<InitialAction, OtherActions...>
    : private DoAllAction<OtherActions...> {
 private:
  using Base = DoAllAction<OtherActions...>;

  // The type of reference that should be provided to an initial action for a
  // mocked function parameter of type T.
  //
  // There are two quirks here:
  //
  //  *  Unlike most forwarding functions, we pass scalars through by value.
  //     This isn't strictly necessary because an lvalue reference would work
  //     fine too and be consistent with other non-reference types, but it's
  //     perhaps less surprising.
  //
  //     For example if the mocked function has signature void(int), then it
  //     might seem surprising for the user's initial action to need to be
  //     convertible to Action<void(const int&)>. This is perhaps less
  //     surprising for a non-scalar type where there may be a performance
  //     impact, or it might even be impossible, to pass by value.
  //
  //  *  More surprisingly, `const T&` is often not a const reference type.
  //     By the reference collapsing rules in C++17 [dcl.ref]/6, if T refers to
  //     U& or U&& for some non-scalar type U, then InitialActionArgType<T> is
  //     U&. In other words, we may hand over a non-const reference.
  //
  //     So for example, given some non-scalar type Obj we have the following
  //     mappings:
  //
  //            T               InitialActionArgType<T>
  //         -------            -----------------------
  //         Obj                const Obj&
  //         Obj&               Obj&
  //         Obj&&              Obj&
  //         const Obj          const Obj&
  //         const Obj&         const Obj&
  //         const Obj&&        const Obj&
  //
  //     In other words, the initial actions get a mutable view of an non-scalar
  //     argument if and only if the mock function itself accepts a non-const
  //     reference type. They are never given an rvalue reference to an
  //     non-scalar type.
  //
  //     This situation makes sense if you imagine use with a matcher that is
  //     designed to write through a reference. For example, if the caller wants
  //     to fill in a reference argument and then return a canned value:
  //
  //         EXPECT_CALL(mock, Call)
  //             .WillOnce(DoAll(SetArgReferee<0>(17), Return(19)));
  //
  template <typename T>
  using InitialActionArgType =
      typename std::conditional<std::is_scalar<T>::value, T, const T&>::type;

 public:
  struct UserConstructorTag {};

  template <typename T, typename... U>
  explicit DoAllAction(UserConstructorTag, T&& initial_action,
                       U&&... other_actions)
      : Base({}, std::forward<U>(other_actions)...),
        initial_action_(std::forward<T>(initial_action)) {}

  template <typename R, typename... Args,
            typename std::enable_if<
                conjunction<
                    // Both the initial action and the rest must support
                    // conversion to OnceAction.
                    std::is_convertible<
                        InitialAction,
                        OnceAction<void(InitialActionArgType<Args>...)>>,
                    std::is_convertible<Base, OnceAction<R(Args...)>>>::value,
                int>::type = 0>
  operator OnceAction<R(Args...)>() && {  // NOLINT
    // Return an action that first calls the initial action with arguments
    // filtered through InitialActionArgType, then forwards arguments directly
    // to the base class to deal with the remaining actions.
    struct OA {
      OnceAction<void(InitialActionArgType<Args>...)> initial_action;
      OnceAction<R(Args...)> remaining_actions;

      R operator()(Args... args) && {
        std::move(initial_action)
            .Call(static_cast<InitialActionArgType<Args>>(args)...);

        return std::move(remaining_actions).Call(std::forward<Args>(args)...);
      }
    };

    return OA{
        std::move(initial_action_),
        std::move(static_cast<Base&>(*this)),
    };
  }

  template <
      typename R, typename... Args,
      typename std::enable_if<
          conjunction<
              // Both the initial action and the rest must support conversion to
              // Action.
              std::is_convertible<const InitialAction&,
                                  Action<void(InitialActionArgType<Args>...)>>,
              std::is_convertible<const Base&, Action<R(Args...)>>>::value,
          int>::type = 0>
  operator Action<R(Args...)>() const {  // NOLINT
    // Return an action that first calls the initial action with arguments
    // filtered through InitialActionArgType, then forwards arguments directly
    // to the base class to deal with the remaining actions.
    struct OA {
      Action<void(InitialActionArgType<Args>...)> initial_action;
      Action<R(Args...)> remaining_actions;

      R operator()(Args... args) const {
        initial_action.Perform(std::forward_as_tuple(
            static_cast<InitialActionArgType<Args>>(args)...));

        return remaining_actions.Perform(
            std::forward_as_tuple(std::forward<Args>(args)...));
      }
    };

    return OA{
        initial_action_,
        static_cast<const Base&>(*this),
    };
  }

 private:
  InitialAction initial_action_;
};

template <typename T, typename... Params>
struct ReturnNewAction {
  T* operator()() const {
    return internal::Apply(
        [](const Params&... unpacked_params) {
          return new T(unpacked_params...);
        },
        params);
  }
  std::tuple<Params...> params;
};

template <size_t k>
struct ReturnArgAction {
  template <typename... Args,
            typename = typename std::enable_if<(k < sizeof...(Args))>::type>
  auto operator()(Args&&... args) const -> decltype(std::get<k>(
      std::forward_as_tuple(std::forward<Args>(args)...))) {
    return std::get<k>(std::forward_as_tuple(std::forward<Args>(args)...));
  }
};

template <size_t k, typename Ptr>
struct SaveArgAction {
  Ptr pointer;

  template <typename... Args>
  void operator()(const Args&... args) const {
    *pointer = std::get<k>(std::tie(args...));
  }
};

template <size_t k, typename Ptr>
struct SaveArgPointeeAction {
  Ptr pointer;

  template <typename... Args>
  void operator()(const Args&... args) const {
    *pointer = *std::get<k>(std::tie(args...));
  }
};

template <size_t k, typename T>
struct SetArgRefereeAction {
  T value;

  template <typename... Args>
  void operator()(Args&&... args) const {
    using argk_type =
        typename ::std::tuple_element<k, std::tuple<Args...>>::type;
    static_assert(std::is_lvalue_reference<argk_type>::value,
                  "Argument must be a reference type.");
    std::get<k>(std::tie(args...)) = value;
  }
};

template <size_t k, typename I1, typename I2>
struct SetArrayArgumentAction {
  I1 first;
  I2 last;

  template <typename... Args>
  void operator()(const Args&... args) const {
    auto value = std::get<k>(std::tie(args...));
    for (auto it = first; it != last; ++it, (void)++value) {
      *value = *it;
    }
  }
};

template <size_t k>
struct DeleteArgAction {
  template <typename... Args>
  void operator()(const Args&... args) const {
    delete std::get<k>(std::tie(args...));
  }
};

template <typename Ptr>
struct ReturnPointeeAction {
  Ptr pointer;
  template <typename... Args>
  auto operator()(const Args&...) const -> decltype(*pointer) {
    return *pointer;
  }
};

#if GTEST_HAS_EXCEPTIONS
template <typename T>
struct ThrowAction {
  T exception;
  // We use a conversion operator to adapt to any return type.
  template <typename R, typename... Args>
  operator Action<R(Args...)>() const {  // NOLINT
    T copy = exception;
    return [copy](Args...) -> R { throw copy; };
  }
};
#endif  // GTEST_HAS_EXCEPTIONS

}  // namespace internal

// An Unused object can be implicitly constructed from ANY value.
// This is handy when defining actions that ignore some or all of the
// mock function arguments.  For example, given
//
//   MOCK_METHOD3(Foo, double(const string& label, double x, double y));
//   MOCK_METHOD3(Bar, double(int index, double x, double y));
//
// instead of
//
//   double DistanceToOriginWithLabel(const string& label, double x, double y) {
//     return sqrt(x*x + y*y);
//   }
//   double DistanceToOriginWithIndex(int index, double x, double y) {
//     return sqrt(x*x + y*y);
//   }
//   ...
//   EXPECT_CALL(mock, Foo("abc", _, _))
//       .WillOnce(Invoke(DistanceToOriginWithLabel));
//   EXPECT_CALL(mock, Bar(5, _, _))
//       .WillOnce(Invoke(DistanceToOriginWithIndex));
//
// you could write
//
//   // We can declare any uninteresting argument as Unused.
//   double DistanceToOrigin(Unused, double x, double y) {
//     return sqrt(x*x + y*y);
//   }
//   ...
//   EXPECT_CALL(mock, Foo("abc", _, _)).WillOnce(Invoke(DistanceToOrigin));
//   EXPECT_CALL(mock, Bar(5, _, _)).WillOnce(Invoke(DistanceToOrigin));
typedef internal::IgnoredValue Unused;

// Creates an action that does actions a1, a2, ..., sequentially in
// each invocation. All but the last action will have a readonly view of the
// arguments.
template <typename... Action>
internal::DoAllAction<typename std::decay<Action>::type...> DoAll(
    Action&&... action) {
  return internal::DoAllAction<typename std::decay<Action>::type...>(
      {}, std::forward<Action>(action)...);
}

// WithArg<k>(an_action) creates an action that passes the k-th
// (0-based) argument of the mock function to an_action and performs
// it.  It adapts an action accepting one argument to one that accepts
// multiple arguments.  For convenience, we also provide
// WithArgs<k>(an_action) (defined below) as a synonym.
template <size_t k, typename InnerAction>
internal::WithArgsAction<typename std::decay<InnerAction>::type, k> WithArg(
    InnerAction&& action) {
  return {std::forward<InnerAction>(action)};
}

// WithArgs<N1, N2, ..., Nk>(an_action) creates an action that passes
// the selected arguments of the mock function to an_action and
// performs it.  It serves as an adaptor between actions with
// different argument lists.
template <size_t k, size_t... ks, typename InnerAction>
internal::WithArgsAction<typename std::decay<InnerAction>::type, k, ks...>
WithArgs(InnerAction&& action) {
  return {std::forward<InnerAction>(action)};
}

// WithoutArgs(inner_action) can be used in a mock function with a
// non-empty argument list to perform inner_action, which takes no
// argument.  In other words, it adapts an action accepting no
// argument to one that accepts (and ignores) arguments.
template <typename InnerAction>
internal::WithArgsAction<typename std::decay<InnerAction>::type> WithoutArgs(
    InnerAction&& action) {
  return {std::forward<InnerAction>(action)};
}

// Creates an action that returns a value.
//
// The returned type can be used with a mock function returning a non-void,
// non-reference type U as follows:
//
//  *  If R is convertible to U and U is move-constructible, then the action can
//     be used with WillOnce.
//
//  *  If const R& is convertible to U and U is copy-constructible, then the
//     action can be used with both WillOnce and WillRepeatedly.
//
// The mock expectation contains the R value from which the U return value is
// constructed (a move/copy of the argument to Return). This means that the R
// value will survive at least until the mock object's expectations are cleared
// or the mock object is destroyed, meaning that U can safely be a
// reference-like type such as std::string_view:
//
//     // The mock function returns a view of a copy of the string fed to
//     // Return. The view is valid even after the action is performed.
//     MockFunction<std::string_view()> mock;
//     EXPECT_CALL(mock, Call).WillOnce(Return(std::string("taco")));
//     const std::string_view result = mock.AsStdFunction()();
//     EXPECT_EQ("taco", result);
//
template <typename R>
internal::ReturnAction<R> Return(R value) {
  return internal::ReturnAction<R>(std::move(value));
}

// Creates an action that returns NULL.
inline PolymorphicAction<internal::ReturnNullAction> ReturnNull() {
  return MakePolymorphicAction(internal::ReturnNullAction());
}

// Creates an action that returns from a void function.
inline PolymorphicAction<internal::ReturnVoidAction> Return() {
  return MakePolymorphicAction(internal::ReturnVoidAction());
}

// Creates an action that returns the reference to a variable.
template <typename R>
inline internal::ReturnRefAction<R> ReturnRef(R& x) {  // NOLINT
  return internal::ReturnRefAction<R>(x);
}

// Prevent using ReturnRef on reference to temporary.
template <typename R, R* = nullptr>
internal::ReturnRefAction<R> ReturnRef(R&&) = delete;

// Creates an action that returns the reference to a copy of the
// argument.  The copy is created when the action is constructed and
// lives as long as the action.
template <typename R>
inline internal::ReturnRefOfCopyAction<R> ReturnRefOfCopy(const R& x) {
  return internal::ReturnRefOfCopyAction<R>(x);
}

// DEPRECATED: use Return(x) directly with WillOnce.
//
// Modifies the parent action (a Return() action) to perform a move of the
// argument instead of a copy.
// Return(ByMove()) actions can only be executed once and will assert this
// invariant.
template <typename R>
internal::ByMoveWrapper<R> ByMove(R x) {
  return internal::ByMoveWrapper<R>(std::move(x));
}

// Creates an action that returns an element of `vals`. Calling this action will
// repeatedly return the next value from `vals` until it reaches the end and
// will restart from the beginning.
template <typename T>
internal::ReturnRoundRobinAction<T> ReturnRoundRobin(std::vector<T> vals) {
  return internal::ReturnRoundRobinAction<T>(std::move(vals));
}

// Creates an action that returns an element of `vals`. Calling this action will
// repeatedly return the next value from `vals` until it reaches the end and
// will restart from the beginning.
template <typename T>
internal::ReturnRoundRobinAction<T> ReturnRoundRobin(
    std::initializer_list<T> vals) {
  return internal::ReturnRoundRobinAction<T>(std::vector<T>(vals));
}

// Creates an action that does the default action for the give mock function.
inline internal::DoDefaultAction DoDefault() {
  return internal::DoDefaultAction();
}

// Creates an action that sets the variable pointed by the N-th
// (0-based) function argument to 'value'.
template <size_t N, typename T>
internal::SetArgumentPointeeAction<N, T> SetArgPointee(T value) {
  return {std::move(value)};
}

// The following version is DEPRECATED.
template <size_t N, typename T>
internal::SetArgumentPointeeAction<N, T> SetArgumentPointee(T value) {
  return {std::move(value)};
}

// Creates an action that sets a pointer referent to a given value.
template <typename T1, typename T2>
PolymorphicAction<internal::AssignAction<T1, T2>> Assign(T1* ptr, T2 val) {
  return MakePolymorphicAction(internal::AssignAction<T1, T2>(ptr, val));
}

#if !GTEST_OS_WINDOWS_MOBILE

// Creates an action that sets errno and returns the appropriate error.
template <typename T>
PolymorphicAction<internal::SetErrnoAndReturnAction<T>> SetErrnoAndReturn(
    int errval, T result) {
  return MakePolymorphicAction(
      internal::SetErrnoAndReturnAction<T>(errval, result));
}

#endif  // !GTEST_OS_WINDOWS_MOBILE

// Various overloads for Invoke().

// Legacy function.
// Actions can now be implicitly constructed from callables. No need to create
// wrapper objects.
// This function exists for backwards compatibility.
template <typename FunctionImpl>
typename std::decay<FunctionImpl>::type Invoke(FunctionImpl&& function_impl) {
  return std::forward<FunctionImpl>(function_impl);
}

// Creates an action that invokes the given method on the given object
// with the mock function's arguments.
template <class Class, typename MethodPtr>
internal::InvokeMethodAction<Class, MethodPtr> Invoke(Class* obj_ptr,
                                                      MethodPtr method_ptr) {
  return {obj_ptr, method_ptr};
}

// Creates an action that invokes 'function_impl' with no argument.
template <typename FunctionImpl>
internal::InvokeWithoutArgsAction<typename std::decay<FunctionImpl>::type>
InvokeWithoutArgs(FunctionImpl function_impl) {
  return {std::move(function_impl)};
}

// Creates an action that invokes the given method on the given object
// with no argument.
template <class Class, typename MethodPtr>
internal::InvokeMethodWithoutArgsAction<Class, MethodPtr> InvokeWithoutArgs(
    Class* obj_ptr, MethodPtr method_ptr) {
  return {obj_ptr, method_ptr};
}

// Creates an action that performs an_action and throws away its
// result.  In other words, it changes the return type of an_action to
// void.  an_action MUST NOT return void, or the code won't compile.
template <typename A>
inline internal::IgnoreResultAction<A> IgnoreResult(const A& an_action) {
  return internal::IgnoreResultAction<A>(an_action);
}

// Creates a reference wrapper for the given L-value.  If necessary,
// you can explicitly specify the type of the reference.  For example,
// suppose 'derived' is an object of type Derived, ByRef(derived)
// would wrap a Derived&.  If you want to wrap a const Base& instead,
// where Base is a base class of Derived, just write:
//
//   ByRef<const Base>(derived)
//
// N.B. ByRef is redundant with std::ref, std::cref and std::reference_wrapper.
// However, it may still be used for consistency with ByMove().
template <typename T>
inline ::std::reference_wrapper<T> ByRef(T& l_value) {  // NOLINT
  return ::std::reference_wrapper<T>(l_value);
}

// The ReturnNew<T>(a1, a2, ..., a_k) action returns a pointer to a new
// instance of type T, constructed on the heap with constructor arguments
// a1, a2, ..., and a_k. The caller assumes ownership of the returned value.
template <typename T, typename... Params>
internal::ReturnNewAction<T, typename std::decay<Params>::type...> ReturnNew(
    Params&&... params) {
  return {std::forward_as_tuple(std::forward<Params>(params)...)};
}

// Action ReturnArg<k>() returns the k-th argument of the mock function.
template <size_t k>
internal::ReturnArgAction<k> ReturnArg() {
  return {};
}

// Action SaveArg<k>(pointer) saves the k-th (0-based) argument of the
// mock function to *pointer.
template <size_t k, typename Ptr>
internal::SaveArgAction<k, Ptr> SaveArg(Ptr pointer) {
  return {pointer};
}

// Action SaveArgPointee<k>(pointer) saves the value pointed to
// by the k-th (0-based) argument of the mock function to *pointer.
template <size_t k, typename Ptr>
internal::SaveArgPointeeAction<k, Ptr> SaveArgPointee(Ptr pointer) {
  return {pointer};
}

// Action SetArgReferee<k>(value) assigns 'value' to the variable
// referenced by the k-th (0-based) argument of the mock function.
template <size_t k, typename T>
internal::SetArgRefereeAction<k, typename std::decay<T>::type> SetArgReferee(
    T&& value) {
  return {std::forward<T>(value)};
}

// Action SetArrayArgument<k>(first, last) copies the elements in
// source range [first, last) to the array pointed to by the k-th
// (0-based) argument, which can be either a pointer or an
// iterator. The action does not take ownership of the elements in the
// source range.
template <size_t k, typename I1, typename I2>
internal::SetArrayArgumentAction<k, I1, I2> SetArrayArgument(I1 first,
                                                             I2 last) {
  return {first, last};
}

// Action DeleteArg<k>() deletes the k-th (0-based) argument of the mock
// function.
template <size_t k>
internal::DeleteArgAction<k> DeleteArg() {
  return {};
}

// This action returns the value pointed to by 'pointer'.
template <typename Ptr>
internal::ReturnPointeeAction<Ptr> ReturnPointee(Ptr pointer) {
  return {pointer};
}

// Action Throw(exception) can be used in a mock function of any type
// to throw the given exception.  Any copyable value can be thrown.
#if GTEST_HAS_EXCEPTIONS
template <typename T>
internal::ThrowAction<typename std::decay<T>::type> Throw(T&& exception) {
  return {std::forward<T>(exception)};
}
#endif  // GTEST_HAS_EXCEPTIONS

namespace internal {

// A macro from the ACTION* family (defined later in gmock-generated-actions.h)
// defines an action that can be used in a mock function.  Typically,
// these actions only care about a subset of the arguments of the mock
// function.  For example, if such an action only uses the second
// argument, it can be used in any mock function that takes >= 2
// arguments where the type of the second argument is compatible.
//
// Therefore, the action implementation must be prepared to take more
// arguments than it needs.  The ExcessiveArg type is used to
// represent those excessive arguments.  In order to keep the compiler
// error messages tractable, we define it in the testing namespace
// instead of testing::internal.  However, this is an INTERNAL TYPE
// and subject to change without notice, so a user MUST NOT USE THIS
// TYPE DIRECTLY.
struct ExcessiveArg {};

// Builds an implementation of an Action<> for some particular signature, using
// a class defined by an ACTION* macro.
template <typename F, typename Impl>
struct ActionImpl;

template <typename Impl>
struct ImplBase {
  struct Holder {
    // Allows each copy of the Action<> to get to the Impl.
    explicit operator const Impl&() const { return *ptr; }
    std::shared_ptr<Impl> ptr;
  };
  using type = typename std::conditional<std::is_constructible<Impl>::value,
                                         Impl, Holder>::type;
};

template <typename R, typename... Args, typename Impl>
struct ActionImpl<R(Args...), Impl> : ImplBase<Impl>::type {
  using Base = typename ImplBase<Impl>::type;
  using function_type = R(Args...);
  using args_type = std::tuple<Args...>;

  ActionImpl() = default;  // Only defined if appropriate for Base.
  explicit ActionImpl(std::shared_ptr<Impl> impl) : Base{std::move(impl)} {}

  R operator()(Args&&... arg) const {
    static constexpr size_t kMaxArgs =
        sizeof...(Args) <= 10 ? sizeof...(Args) : 10;
    return Apply(MakeIndexSequence<kMaxArgs>{},
                 MakeIndexSequence<10 - kMaxArgs>{},
                 args_type{std::forward<Args>(arg)...});
  }

  template <std::size_t... arg_id, std::size_t... excess_id>
  R Apply(IndexSequence<arg_id...>, IndexSequence<excess_id...>,
          const args_type& args) const {
    // Impl need not be specific to the signature of action being implemented;
    // only the implementing function body needs to have all of the specific
    // types instantiated.  Up to 10 of the args that are provided by the
    // args_type get passed, followed by a dummy of unspecified type for the
    // remainder up to 10 explicit args.
    static constexpr ExcessiveArg kExcessArg{};
    return static_cast<const Impl&>(*this)
        .template gmock_PerformImpl<
            /*function_type=*/function_type, /*return_type=*/R,
            /*args_type=*/args_type,
            /*argN_type=*/
            typename std::tuple_element<arg_id, args_type>::type...>(
            /*args=*/args, std::get<arg_id>(args)...,
            ((void)excess_id, kExcessArg)...);
  }
};

// Stores a default-constructed Impl as part of the Action<>'s
// std::function<>. The Impl should be trivial to copy.
template <typename F, typename Impl>
::testing::Action<F> MakeAction() {
  return ::testing::Action<F>(ActionImpl<F, Impl>());
}

// Stores just the one given instance of Impl.
template <typename F, typename Impl>
::testing::Action<F> MakeAction(std::shared_ptr<Impl> impl) {
  return ::testing::Action<F>(ActionImpl<F, Impl>(std::move(impl)));
}

#define GMOCK_INTERNAL_ARG_UNUSED(i, data, el) \
  , const arg##i##_type& arg##i GTEST_ATTRIBUTE_UNUSED_
#define GMOCK_ACTION_ARG_TYPES_AND_NAMES_UNUSED_                 \
  const args_type& args GTEST_ATTRIBUTE_UNUSED_ GMOCK_PP_REPEAT( \
      GMOCK_INTERNAL_ARG_UNUSED, , 10)

#define GMOCK_INTERNAL_ARG(i, data, el) , const arg##i##_type& arg##i
#define GMOCK_ACTION_ARG_TYPES_AND_NAMES_ \
  const args_type& args GMOCK_PP_REPEAT(GMOCK_INTERNAL_ARG, , 10)

#define GMOCK_INTERNAL_TEMPLATE_ARG(i, data, el) , typename arg##i##_type
#define GMOCK_ACTION_TEMPLATE_ARGS_NAMES_ \
  GMOCK_PP_TAIL(GMOCK_PP_REPEAT(GMOCK_INTERNAL_TEMPLATE_ARG, , 10))

#define GMOCK_INTERNAL_TYPENAME_PARAM(i, data, param) , typename param##_type
#define GMOCK_ACTION_TYPENAME_PARAMS_(params) \
  GMOCK_PP_TAIL(GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_TYPENAME_PARAM, , params))

#define GMOCK_INTERNAL_TYPE_PARAM(i, data, param) , param##_type
#define GMOCK_ACTION_TYPE_PARAMS_(params) \
  GMOCK_PP_TAIL(GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_TYPE_PARAM, , params))

#define GMOCK_INTERNAL_TYPE_GVALUE_PARAM(i, data, param) \
  , param##_type gmock_p##i
#define GMOCK_ACTION_TYPE_GVALUE_PARAMS_(params) \
  GMOCK_PP_TAIL(GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_TYPE_GVALUE_PARAM, , params))

#define GMOCK_INTERNAL_GVALUE_PARAM(i, data, param) \
  , std::forward<param##_type>(gmock_p##i)
#define GMOCK_ACTION_GVALUE_PARAMS_(params) \
  GMOCK_PP_TAIL(GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_GVALUE_PARAM, , params))

#define GMOCK_INTERNAL_INIT_PARAM(i, data, param) \
  , param(::std::forward<param##_type>(gmock_p##i))
#define GMOCK_ACTION_INIT_PARAMS_(params) \
  GMOCK_PP_TAIL(GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_INIT_PARAM, , params))

#define GMOCK_INTERNAL_FIELD_PARAM(i, data, param) param##_type param;
#define GMOCK_ACTION_FIELD_PARAMS_(params) \
  GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_FIELD_PARAM, , params)

#define GMOCK_INTERNAL_ACTION(name, full_name, params)                         \
  template <GMOCK_ACTION_TYPENAME_PARAMS_(params)>                             \
  class full_name {                                                            \
   public:                                                                     \
    explicit full_name(GMOCK_ACTION_TYPE_GVALUE_PARAMS_(params))               \
        : impl_(std::make_shared<gmock_Impl>(                                  \
              GMOCK_ACTION_GVALUE_PARAMS_(params))) {}                         \
    full_name(const full_name&) = default;                                     \
    full_name(full_name&&) noexcept = default;                                 \
    template <typename F>                                                      \
    operator ::testing::Action<F>() const {                                    \
      return ::testing::internal::MakeAction<F>(impl_);                        \
    }                                                                          \
                                                                               \
   private:                                                                    \
    class gmock_Impl {                                                         \
     public:                                                                   \
      explicit gmock_Impl(GMOCK_ACTION_TYPE_GVALUE_PARAMS_(params))            \
          : GMOCK_ACTION_INIT_PARAMS_(params) {}                               \
      template <typename function_type, typename return_type,                  \
                typename args_type, GMOCK_ACTION_TEMPLATE_ARGS_NAMES_>         \
      return_type gmock_PerformImpl(GMOCK_ACTION_ARG_TYPES_AND_NAMES_) const;  \
      GMOCK_ACTION_FIELD_PARAMS_(params)                                       \
    };                                                                         \
    std::shared_ptr<const gmock_Impl> impl_;                                   \
  };                                                                           \
  template <GMOCK_ACTION_TYPENAME_PARAMS_(params)>                             \
  inline full_name<GMOCK_ACTION_TYPE_PARAMS_(params)> name(                    \
      GMOCK_ACTION_TYPE_GVALUE_PARAMS_(params)) GTEST_MUST_USE_RESULT_;        \
  template <GMOCK_ACTION_TYPENAME_PARAMS_(params)>                             \
  inline full_name<GMOCK_ACTION_TYPE_PARAMS_(params)> name(                    \
      GMOCK_ACTION_TYPE_GVALUE_PARAMS_(params)) {                              \
    return full_name<GMOCK_ACTION_TYPE_PARAMS_(params)>(                       \
        GMOCK_ACTION_GVALUE_PARAMS_(params));                                  \
  }                                                                            \
  template <GMOCK_ACTION_TYPENAME_PARAMS_(params)>                             \
  template <typename function_type, typename return_type, typename args_type,  \
            GMOCK_ACTION_TEMPLATE_ARGS_NAMES_>                                 \
  return_type                                                                  \
  full_name<GMOCK_ACTION_TYPE_PARAMS_(params)>::gmock_Impl::gmock_PerformImpl( \
      GMOCK_ACTION_ARG_TYPES_AND_NAMES_UNUSED_) const

}  // namespace internal

// Similar to GMOCK_INTERNAL_ACTION, but no bound parameters are stored.
#define ACTION(name)                                                          \
  class name##Action {                                                        \
   public:                                                                    \
    explicit name##Action() noexcept {}                                       \
    name##Action(const name##Action&) noexcept {}                             \
    template <typename F>                                                     \
    operator ::testing::Action<F>() const {                                   \
      return ::testing::internal::MakeAction<F, gmock_Impl>();                \
    }                                                                         \
                                                                              \
   private:                                                                   \
    class gmock_Impl {                                                        \
     public:                                                                  \
      template <typename function_type, typename return_type,                 \
                typename args_type, GMOCK_ACTION_TEMPLATE_ARGS_NAMES_>        \
      return_type gmock_PerformImpl(GMOCK_ACTION_ARG_TYPES_AND_NAMES_) const; \
    };                                                                        \
  };                                                                          \
  inline name##Action name() GTEST_MUST_USE_RESULT_;                          \
  inline name##Action name() { return name##Action(); }                       \
  template <typename function_type, typename return_type, typename args_type, \
            GMOCK_ACTION_TEMPLATE_ARGS_NAMES_>                                \
  return_type name##Action::gmock_Impl::gmock_PerformImpl(                    \
      GMOCK_ACTION_ARG_TYPES_AND_NAMES_UNUSED_) const

#define ACTION_P(name, ...) \
  GMOCK_INTERNAL_ACTION(name, name##ActionP, (__VA_ARGS__))

#define ACTION_P2(name, ...) \
  GMOCK_INTERNAL_ACTION(name, name##ActionP2, (__VA_ARGS__))

#define ACTION_P3(name, ...) \
  GMOCK_INTERNAL_ACTION(name, name##ActionP3, (__VA_ARGS__))

#define ACTION_P4(name, ...) \
  GMOCK_INTERNAL_ACTION(name, name##ActionP4, (__VA_ARGS__))

#define ACTION_P5(name, ...) \
  GMOCK_INTERNAL_ACTION(name, name##ActionP5, (__VA_ARGS__))

#define ACTION_P6(name, ...) \
  GMOCK_INTERNAL_ACTION(name, name##ActionP6, (__VA_ARGS__))

#define ACTION_P7(name, ...) \
  GMOCK_INTERNAL_ACTION(name, name##ActionP7, (__VA_ARGS__))

#define ACTION_P8(name, ...) \
  GMOCK_INTERNAL_ACTION(name, name##ActionP8, (__VA_ARGS__))

#define ACTION_P9(name, ...) \
  GMOCK_INTERNAL_ACTION(name, name##ActionP9, (__VA_ARGS__))

#define ACTION_P10(name, ...) \
  GMOCK_INTERNAL_ACTION(name, name##ActionP10, (__VA_ARGS__))

}  // namespace testing

#ifdef _MSC_VER
#pragma warning(pop)
#endif

#endif  // GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_ACTIONS_H_