tests/ui/const-generics/min_const_generics/macro.rs

   1 // run-pass
   2 struct Example<const N: usize>;
   3
   4 macro_rules! external_macro {
   5   () => {{
   6     const X: usize = 1337;
   7     X
   8   }}
   9 }
  10
  11 trait Marker<const N: usize> {}
  12 impl<const N: usize> Marker<N> for Example<N> {}
  13
  14 fn make_marker() -> impl Marker<{
  15     #[macro_export]
  16     macro_rules! const_macro { () => {{ 3 }} } inline!()
  17 }> {
  18   Example::<{ const_macro!() }>
  19 }
  20
  21 fn from_marker(_: impl Marker<{
  22     #[macro_export]
  23     macro_rules! inline { () => {{ 3 }} } inline!()
  24 }>) {}
  25
  26 fn main() {
  27   let _ok = Example::<{
  28     #[macro_export]
  29     macro_rules! gimme_a_const {
  30       ($rusty: ident) => {{ let $rusty = 3; *&$rusty }}
  31     }
  32     gimme_a_const!(run)
  33   }>;
  34
  35   let _ok = Example::<{ external_macro!() }>;
  36
  37   let _ok: [_; gimme_a_const!(blah)] = [0,0,0];
  38   let _ok: [[u8; gimme_a_const!(blah)]; gimme_a_const!(blah)];
  39   let _ok: [u8; gimme_a_const!(blah)];
  40
  41   let _ok: [u8; {
  42     #[macro_export]
  43     macro_rules! const_two { () => {{ 2 }} }
  44     const_two!()
  45   }];
  46
  47   let _ok = [0; {
  48     #[macro_export]
  49     macro_rules! const_three { () => {{ 3 }} }
  50     const_three!()
  51   }];
  52   let _ok = [0; const_three!()];
  53
  54   from_marker(make_marker());
  55 }