File: mbe-bare-trait-objects-const-trait-bounds.rs

package info (click to toggle)
rustc 1.85.0%2Bdfsg2-3
  • links: PTS, VCS
  • area: main
  • in suites: trixie
  • size: 893,176 kB
  • sloc: xml: 158,127; python: 35,830; javascript: 19,497; cpp: 19,002; sh: 17,245; ansic: 13,127; asm: 4,376; makefile: 1,051; lisp: 29; perl: 29; ruby: 19; sql: 11
file content (20 lines) | stat: -rw-r--r-- 641 bytes parent folder | download | duplicates (13)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
// Ensure that we don't consider `const Trait` and `~const Trait` to
// match the macro fragment specifier `ty` as that would be a breaking
// change theoretically speaking. Syntactically trait object types can
// be "bare", i.e., lack the prefix `dyn`.
// By contrast, `?Trait` *does* match `ty` and therefore an arm like
// `?$Trait:path` would never be reached.
// See `parser/macro/mbe-bare-trait-object-maybe-trait-bound.rs`.

//@ check-pass

macro_rules! check {
    ($Type:ty) => { compile_error!("ty"); };
    (const $Trait:path) => {};
    (~const $Trait:path) => {};
}

check! { const Trait }
check! { ~const Trait }

fn main() {}