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// Copyright 2021 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package assignability
// See the end of this package for the declarations
// of the types and variables used in these tests.
// "x's type is identical to T"
func _[TP any](X TP) {
b = b
a = a
l = l
s = s
p = p
f = f
i = i
m = m
c = c
d = d
B = B
A = A
L = L
S = S
P = P
F = F
I = I
M = M
C = C
D = D
X = X
}
// "x's type V and T have identical underlying types
// and at least one of V or T is not a named type."
// (here a named type is a type with a name)
func _[TP1, TP2 Interface](X1 TP1, X2 TP2) {
b = B // ERROR cannot use B .* as int value
a = A
l = L
s = S
p = P
f = F
i = I
m = M
c = C
d = D
B = b // ERROR cannot use b .* as Basic value
A = a
L = l
S = s
P = p
F = f
I = i
M = m
C = c
D = d
X1 = i // ERROR cannot use i .* as TP1 value
X1 = X2 // ERROR cannot use X2 .* as TP1 value
}
// "T is an interface type and x implements T and T is not a type parameter"
func _[TP Interface](X TP) {
i = d // ERROR missing method m
i = D
i = X
X = i // ERROR cannot use i .* as TP value
}
// "x is a bidirectional channel value, T is a channel type, x's type V and T have identical element types, and at least one of V or T is not a named type"
// (here a named type is a type with a name)
type (
_SendChan = chan<- int
_RecvChan = <-chan int
SendChan _SendChan
RecvChan _RecvChan
)
func _[
_CC ~_Chan,
_SC ~_SendChan,
_RC ~_RecvChan,
CC Chan,
SC SendChan,
RC RecvChan,
]() {
var (
_ _SendChan = c
_ _RecvChan = c
_ _Chan = c
_ _SendChan = C
_ _RecvChan = C
_ _Chan = C
_ SendChan = c
_ RecvChan = c
_ Chan = c
_ SendChan = C // ERROR cannot use C .* as SendChan value
_ RecvChan = C // ERROR cannot use C .* as RecvChan value
_ Chan = C
_ Chan = make /* ERROR cannot use make\(chan Basic\) .* as Chan value */ (chan Basic)
)
var (
_ _CC = C // ERROR cannot use C .* as _CC value
_ _SC = C // ERROR cannot use C .* as _SC value
_ _RC = C // ERROR cannot use C .* as _RC value
_ CC = _CC /* ERROR cannot use _CC\(nil\) .* as CC value */ (nil)
_ SC = _CC /* ERROR cannot use _CC\(nil\) .* as SC value */ (nil)
_ RC = _CC /* ERROR cannot use _CC\(nil\) .* as RC value */ (nil)
_ CC = C // ERROR cannot use C .* as CC value
_ SC = C // ERROR cannot use C .* as SC value
_ RC = C // ERROR cannot use C .* as RC value
)
}
// "x's type V is not a named type and T is a type parameter, and x is assignable to each specific type in T's type set."
func _[
TP0 any,
TP1 ~_Chan,
TP2 ~chan int | ~chan byte,
]() {
var (
_ TP0 = c // ERROR cannot use c .* as TP0 value
_ TP0 = C // ERROR cannot use C .* as TP0 value
_ TP1 = c
_ TP1 = C // ERROR cannot use C .* as TP1 value
_ TP2 = c // ERROR .* cannot assign chan int to chan byte
)
}
// "x's type V is a type parameter and T is not a named type, and values x' of each specific type in V's type set are assignable to T."
func _[
TP0 Interface,
TP1 ~_Chan,
TP2 ~chan int | ~chan byte,
](X0 TP0, X1 TP1, X2 TP2) {
i = X0
I = X0
c = X1
C = X1 // ERROR cannot use X1 .* as Chan value
c = X2 // ERROR .* cannot assign chan byte \(in TP2\) to chan int
}
// "x is the predeclared identifier nil and T is a pointer, function, slice, map, channel, or interface type"
func _[TP Interface](X TP) {
b = nil // ERROR cannot use nil
a = nil // ERROR cannot use nil
l = nil
s = nil // ERROR cannot use nil
p = nil
f = nil
i = nil
m = nil
c = nil
d = nil // ERROR cannot use nil
B = nil // ERROR cannot use nil
A = nil // ERROR cannot use nil
L = nil
S = nil // ERROR cannot use nil
P = nil
F = nil
I = nil
M = nil
C = nil
D = nil // ERROR cannot use nil
X = nil // ERROR cannot use nil
}
// "x is an untyped constant representable by a value of type T"
func _[
Int8 ~int8,
Int16 ~int16,
Int32 ~int32,
Int64 ~int64,
Int8_16 ~int8 | ~int16,
](
i8 Int8,
i16 Int16,
i32 Int32,
i64 Int64,
i8_16 Int8_16,
) {
b = 42
b = 42.0
// etc.
i8 = -1 << 7
i8 = 1<<7 - 1
i16 = -1 << 15
i16 = 1<<15 - 1
i32 = -1 << 31
i32 = 1<<31 - 1
i64 = -1 << 63
i64 = 1<<63 - 1
i8_16 = -1 << 7
i8_16 = 1<<7 - 1
i8_16 = - /* ERROR cannot use .* as Int8_16 */ 1 << 15
i8_16 = 1 /* ERROR cannot use .* as Int8_16 */ <<15 - 1
}
// proto-types for tests
type (
_Basic = int
_Array = [10]int
_Slice = []int
_Struct = struct{ f int }
_Pointer = *int
_Func = func(x int) string
_Interface = interface{ m() int }
_Map = map[string]int
_Chan = chan int
Basic _Basic
Array _Array
Slice _Slice
Struct _Struct
Pointer _Pointer
Func _Func
Interface _Interface
Map _Map
Chan _Chan
Defined _Struct
)
func (Defined) m() int
// proto-variables for tests
var (
b _Basic
a _Array
l _Slice
s _Struct
p _Pointer
f _Func
i _Interface
m _Map
c _Chan
d _Struct
B Basic
A Array
L Slice
S Struct
P Pointer
F Func
I Interface
M Map
C Chan
D Defined
)
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