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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:13 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:13 +0000 |
commit | 218caa410aa38c29984be31a5229b9fa717560ee (patch) | |
tree | c54bd55eeb6e4c508940a30e94c0032fbd45d677 /tests/ui/macros/rfc-3086-metavar-expr/feature-gate-macro_metavar_expr.rs | |
parent | Releasing progress-linux version 1.67.1+dfsg1-1~progress7.99u1. (diff) | |
download | rustc-218caa410aa38c29984be31a5229b9fa717560ee.tar.xz rustc-218caa410aa38c29984be31a5229b9fa717560ee.zip |
Merging upstream version 1.68.2+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tests/ui/macros/rfc-3086-metavar-expr/feature-gate-macro_metavar_expr.rs')
-rw-r--r-- | tests/ui/macros/rfc-3086-metavar-expr/feature-gate-macro_metavar_expr.rs | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/tests/ui/macros/rfc-3086-metavar-expr/feature-gate-macro_metavar_expr.rs b/tests/ui/macros/rfc-3086-metavar-expr/feature-gate-macro_metavar_expr.rs new file mode 100644 index 000000000..d05cd1b31 --- /dev/null +++ b/tests/ui/macros/rfc-3086-metavar-expr/feature-gate-macro_metavar_expr.rs @@ -0,0 +1,148 @@ +// run-pass + +#![feature(macro_metavar_expr)] + +/// Count the number of idents in a macro repetition. +macro_rules! count_idents { + ( $( $i:ident ),* ) => { + ${count(i)} + }; +} + +/// Count the number of idents in a 2-dimensional macro repetition. +macro_rules! count_idents_2 { + ( $( [ $( $i:ident ),* ] ),* ) => { + ${count(i)} + }; +} + +/// Mostly counts the number of OUTER-MOST repetitions +macro_rules! count_depth_limits { + ( $( { $( [ $( $outer:ident : ( $( $inner:ident )* ) )* ] )* } )* ) => { + ( + ( + ${count(inner)}, + ${count(inner, 0)}, + ${count(inner, 1)}, + ${count(inner, 2)}, + ${count(inner, 3)}, + ), + ( + ${count(outer)}, + ${count(outer, 0)}, + ${count(outer, 1)}, + ${count(outer, 2)}, + ), + ) + }; +} + +/// Produce (index, length) pairs for literals in a macro repetition. +/// The literal is not included in the output, so this macro uses the +/// `ignore` meta-variable expression to create a non-expanding +/// repetition binding. +macro_rules! enumerate_literals { + ( $( ($l:stmt) ),* ) => { + [$( ${ignore(l)} (${index()}, ${length()}) ),*] + }; +} + +/// Produce index and length tuples for literals in a 2-dimensional +/// macro repetition. +macro_rules! enumerate_literals_2 { + ( $( [ $( ($l:literal) ),* ] ),* ) => { + [ + $( + $( + ( + ${index(1)}, + ${length(1)}, + ${index(0)}, + ${length(0)}, + $l + ), + )* + )* + ] + }; +} + +/// Generate macros that count idents and then add a constant number +/// to the count. +/// +/// This macro uses dollar escaping to make it unambiguous as to which +/// macro the repetition belongs to. +macro_rules! make_count_adders { + ( $( $i:ident, $b:literal );* ) => { + $( + macro_rules! $i { + ( $$( $$j:ident ),* ) => { + $b + $${count(j)} + }; + } + )* + }; +} + +make_count_adders! { plus_one, 1; plus_five, 5 } + +/// Generate a macro that allows selection of a particular literal +/// from a sequence of inputs by their identifier. +/// +/// This macro uses dollar escaping to make it unambiguous as to which +/// macro the repetition belongs to, and to allow expansion of an +/// identifier the name of which is not known in the definition +/// of `make_picker`. +macro_rules! make_picker { + ( $m:ident => $( $i:ident ),* ; $p:ident ) => { + macro_rules! $m { + ( $( $$ $i:literal ),* ) => { + $$ $p + }; + } + }; +} + +make_picker!(first => a, b; a); + +make_picker!(second => a, b; b); + +fn main() { + assert_eq!(count_idents!(a, b, c), 3); + assert_eq!(count_idents_2!([a, b, c], [d, e], [f]), 6); + assert_eq!( + count_depth_limits! { + { + [ A: (a b c) D: (d e f) ] + [ G: (g h) I: (i j k l m) ] + [ N: (n) ] + } + { + [ O: (o) P: (p q) R: (r s) ] + [ T: (t u v w x y z) ] + } + }, + ((26, 2, 5, 9, 26), (9, 2, 5, 9)) + ); + assert_eq!(enumerate_literals![("foo"), ("bar")], [(0, 2), (1, 2)]); + assert_eq!( + enumerate_literals_2![ + [("foo"), ("bar"), ("baz")], + [("qux"), ("quux"), ("quuz"), ("xyzzy")] + ], + [ + (0, 2, 0, 3, "foo"), + (0, 2, 1, 3, "bar"), + (0, 2, 2, 3, "baz"), + + (1, 2, 0, 4, "qux"), + (1, 2, 1, 4, "quux"), + (1, 2, 2, 4, "quuz"), + (1, 2, 3, 4, "xyzzy"), + ] + ); + assert_eq!(plus_one!(a, b, c), 4); + assert_eq!(plus_five!(a, b), 7); + assert_eq!(first!(1, 2), 1); + assert_eq!(second!(1, 2), 2); +} |