src/test/ui/rustc-args-required-const.rs

   1 #![feature(rustc_attrs, const_fn)]
   2
   3 #[rustc_args_required_const(0)]
   4 fn foo(_a: i32) {
   5 }
   6
   7 #[rustc_args_required_const(1)]
   8 fn bar(_a: i32, _b: i32) {
   9 }
  10
  11 const A: i32 = 3;
  12
  13 const fn baz() -> i32 {
  14     3
  15 }
  16
  17 fn main() {
  18     foo(2);
  19     foo(2 + 3);
  20     const BAZ: i32 = baz();
  21     foo(BAZ);
  22     let a = 4;
  23     foo(A);
  24     foo(a); //~ ERROR: argument 1 is required to be a constant
  25     bar(a, 3);
  26     bar(a, a); //~ ERROR: argument 2 is required to be a constant
  27 }