| // Copyright 2015 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| // Test use of advanced const fn without the `const_fn` feature gate. |
| |
| const fn foo() -> usize { 0 } // ok |
| |
| trait Foo { |
| const fn foo() -> u32; //~ ERROR const fn is unstable |
| //~| ERROR trait fns cannot be declared const |
| const fn bar() -> u32 { 0 } //~ ERROR const fn is unstable |
| //~| ERROR trait fns cannot be declared const |
| } |
| |
| impl Foo { |
| const fn baz() -> u32 { 0 } // ok |
| } |
| |
| impl Foo for u32 { |
| const fn foo() -> u32 { 0 } //~ ERROR trait fns cannot be declared const |
| } |
| |
| static FOO: usize = foo(); |
| const BAR: usize = foo(); |
| |
| macro_rules! constant { |
| ($n:ident: $t:ty = $v:expr) => { |
| const $n: $t = $v; |
| } |
| } |
| |
| constant! { |
| BAZ: usize = foo() |
| } |
| |
| fn main() { |
| let x: [usize; foo()] = []; |
| } |