git.proxmox.com Git - rustc.git/blob

   1 // Copyright 2016 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 // Test a case where we setup relationships like `'x: 'a` or `'a: 'x`,
  12 // where `'x` is bound in closure type but `'a` is free. This forces
  13 // us to approximate `'x` one way or the other.
  14
  15 // compile-flags:-Znll -Zborrowck=mir -Zverbose
  16
  17 #![feature(rustc_attrs)]
  18
  19 use std::cell::Cell;
  20
  21 fn foo<'a, F>(_cell: Cell<&'a u32>, _f: F)
  22 where
  23     F: for<'x> FnOnce(Cell<&'a u32>, Cell<&'x u32>),
  24 {
  25 }
  26
  27 #[rustc_regions]
  28 fn case1() {
  29     let a = 0;
  30     let cell = Cell::new(&a);
  31     foo(cell, |cell_a, cell_x| {
  32         //~^ WARNING not reporting region error due to -Znll
  33         cell_a.set(cell_x.get()); // forces 'x: 'a, error in closure
  34         //~^ ERROR does not outlive free region
  35     })
  36 }
  37
  38 #[rustc_regions]
  39 fn case2() {
  40     let a = 0;
  41     let cell = Cell::new(&a);
  42     //~^ ERROR `a` does not live long enough
  43
  44     // As you can see in the stderr output, this closure propoagates a
  45     // requirement that `'a: 'static'.
  46     foo(cell, |cell_a, cell_x| {
  47         cell_x.set(cell_a.get()); // forces 'a: 'x, implies 'a = 'static -> borrow error
  48     })
  49 }
  50
  51 fn main() { }