src/test/run-pass/regions-fn-subtyping.rs

   1 // Copyright 2012 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 // Issue #2263.
  12
  13 // Should pass region checking.
  14 fn ok(f: @fn(x: &uint)) {
  15     // Here, g is a function that can accept a uint pointer with
  16     // lifetime r, and f is a function that can accept a uint pointer
  17     // with any lifetime.  The assignment g = f should be OK (i.e.,
  18     // f's type should be a subtype of g's type), because f can be
  19     // used in any context that expects g's type.  But this currently
  20     // fails.
  21     let mut g: @fn<'r>(y: &'r uint) = |x| { };
  22     g = f;
  23 }
  24
  25 // This version is the same as above, except that here, g's type is
  26 // inferred.
  27 fn ok_inferred(f: @fn(x: &uint)) {
  28     let mut g: @fn<'r>(x: &'r uint) = |_| {};
  29     g = f;
  30 }
  31
  32 pub fn main() {
  33 }