src/test/run-pass/macro-stmt.rs

   1 // Copyright 2012-2014 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 macro_rules! myfn {
  12     ( $f:ident, ( $( $x:ident ),* ), $body:block ) => (
  13         fn $f( $( $x : isize),* ) -> isize $body
  14     )
  15 }
  16
  17 myfn!(add, (a,b), { return a+b; } );
  18
  19 pub fn main() {
  20
  21     macro_rules! mylet {
  22         ($x:ident, $val:expr) => (
  23             let $x = $val;
  24         )
  25     }
  26
  27     mylet!(y, 8*2);
  28     assert_eq!(y, 16);
  29
  30     myfn!(mult, (a,b), { a*b } );
  31
  32     assert_eq!(mult(2, add(4,4)), 16);
  33
  34     macro_rules! actually_an_expr_macro {
  35         () => ( 16 )
  36     }
  37
  38     assert_eq!({ actually_an_expr_macro!() }, 16);
  39
  40 }