src/test/compile-fail/borrowck/borrowck-call-is-borrow-issue-12224.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 // Ensure that invoking a closure counts as a unique immutable borrow
  12
  13 type Fn<'a> = Box<FnMut() + 'a>;
  14
  15 struct Test<'a> {
  16     f: Box<FnMut() + 'a>
  17 }
  18
  19 // FIXME (#22405): Replace `Box::new` with `box` here when/if possible.
  20 fn call<F>(mut f: F) where F: FnMut(Fn) {
  21     f(Box::new(|| {
  22     //~^ ERROR: cannot borrow `f` as mutable more than once
  23         f((Box::new(|| {})))
  24     }));
  25 }
  26
  27 fn test1() {
  28     call(|mut a| {
  29         a.call_mut(());
  30     });
  31 }
  32
  33 fn test2<F>(f: &F) where F: FnMut() {
  34     (*f)(); //~ ERROR: cannot borrow immutable borrowed content `*f` as mutable
  35 }
  36
  37 fn test3<F>(f: &mut F) where F: FnMut() {
  38     (*f)();
  39 }
  40
  41 fn test4(f: &Test) {
  42     f.f.call_mut(()) //~ ERROR: cannot borrow immutable `Box` content `*f.f` as mutable
  43 }
  44
  45 fn test5(f: &mut Test) {
  46     f.f.call_mut(())
  47 }
  48
  49 fn test6() {
  50     let mut f = || {};
  51     (|| {
  52         f();
  53     })();
  54 }
  55
  56 fn test7() {
  57     fn foo<F>(_: F) where F: FnMut(Box<FnMut(isize)>, isize) {}
  58     let mut f = |g: Box<FnMut(isize)>, b: isize| {};
  59     // FIXME (#22405): Replace `Box::new` with `box` here when/if possible.
  60     f(Box::new(|a| {
  61         foo(f);
  62         //~^ ERROR cannot move `f` into closure because it is borrowed
  63         //~| ERROR cannot move out of captured outer variable in an `FnMut` closure
  64     }), 3);
  65 }
  66
  67 fn main() {}