src/test/run-pass/const-block-item-macro-codegen.rs

   1 // Copyright 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 // General test that function items in static blocks
  12 // can be generated with a macro.
  13
  14 struct MyType {
  15     desc: &'static str,
  16     data: uint,
  17     code: fn(uint, uint) -> uint
  18 }
  19
  20 impl MyType {
  21     fn eval(&self, a: uint) -> uint {
  22         (self.code)(self.data, a)
  23     }
  24 }
  25
  26 macro_rules! codegen {
  27     ($e:expr, $v:expr) => {
  28         {
  29             fn generated(a: uint, b: uint) -> uint {
  30                 a - ($e * b)
  31             }
  32             MyType {
  33                 desc: "test",
  34                 data: $v,
  35                 code: generated
  36             }
  37         }
  38     }
  39 }
  40
  41 static GENERATED_CODE_1: MyType = codegen!(2, 100);
  42 static GENERATED_CODE_2: MyType = codegen!(5, 1000);
  43
  44 pub fn main() {
  45     assert_eq!(GENERATED_CODE_1.eval(10), 80);
  46     assert_eq!(GENERATED_CODE_2.eval(100), 500);
  47 }