src/test/compile-fail/closure-no-fn.rs

   1 // Copyright 2017 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 // Ensure that capturing closures are never coerced to fns
  12 // Especially interesting as non-capturing closures can be.
  13
  14 fn main() {
  15     let mut a = 0u8;
  16     let foo: fn(u8) -> u8 = |v: u8| { a += v; a };
  17     //~^ ERROR mismatched types
  18     let b = 0u8;
  19     let bar: fn() -> u8 = || { b };
  20     //~^ ERROR mismatched types
  21     let baz: fn() -> u8 = || { b } as fn() -> u8;
  22     //~^ ERROR mismatched types
  23     //~^^ ERROR non-scalar cast
  24 }