src/test/run-pass/const-fn.rs

   1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 // A very basic test of const fn functionality.
  12
  13 #![feature(const_fn)]
  14
  15 const fn add(x: u32, y: u32) -> u32 {
  16     x + y
  17 }
  18
  19 const fn sub(x: u32, y: u32) -> u32 {
  20     x - y
  21 }
  22
  23 const SUM: u32 = add(44, 22);
  24 const DIFF: u32 = sub(44, 22);
  25
  26 fn main() {
  27     assert_eq!(SUM, 66);
  28     assert!(SUM != 88);
  29
  30     assert_eq!(DIFF, 22);
  31
  32 }