tests/ui/borrowck/borrowck-overloaded-call.rs

   1 #![feature(fn_traits, unboxed_closures)]
   2
   3 use std::ops::{Fn, FnMut, FnOnce};
   4
   5 struct SFn {
   6     x: isize,
   7     y: isize,
   8 }
   9
  10 impl Fn<(isize,)> for SFn {
  11     extern "rust-call" fn call(&self, (z,): (isize,)) -> isize {
  12         self.x * self.y * z
  13     }
  14 }
  15
  16 impl FnMut<(isize,)> for SFn {
  17     extern "rust-call" fn call_mut(&mut self, args: (isize,)) -> isize { self.call(args) }
  18 }
  19
  20 impl FnOnce<(isize,)> for SFn {
  21     type Output = isize;
  22     extern "rust-call" fn call_once(self, args: (isize,)) -> isize { self.call(args) }
  23 }
  24
  25 struct SFnMut {
  26     x: isize,
  27     y: isize,
  28 }
  29
  30 impl FnMut<(isize,)> for SFnMut {
  31     extern "rust-call" fn call_mut(&mut self, (z,): (isize,)) -> isize {
  32         self.x * self.y * z
  33     }
  34 }
  35
  36 impl FnOnce<(isize,)> for SFnMut {
  37     type Output = isize;
  38     extern "rust-call" fn call_once(mut self, args: (isize,)) -> isize { self.call_mut(args) }
  39 }
  40
  41 struct SFnOnce {
  42     x: String,
  43 }
  44
  45 impl FnOnce<(String,)> for SFnOnce {
  46     type Output = usize;
  47
  48     extern "rust-call" fn call_once(self, (z,): (String,)) -> usize {
  49         self.x.len() + z.len()
  50     }
  51 }
  52
  53 fn f() {
  54     let mut s = SFn {
  55         x: 1,
  56         y: 2,
  57     };
  58     let sp = &mut s;
  59     s(3);   //~ ERROR cannot borrow `s` as immutable because it is also borrowed as mutable
  60     use_mut(sp);
  61 }
  62 fn g() {
  63     let s = SFnMut {
  64         x: 1,
  65         y: 2,
  66     };
  67     s(3);   //~ ERROR cannot borrow `s` as mutable, as it is not declared as mutable
  68 }
  69
  70 fn h() {
  71     let s = SFnOnce {
  72         x: "hello".to_string(),
  73     };
  74     s(" world".to_string());
  75     s(" world".to_string());    //~ ERROR use of moved value: `s`
  76 }
  77
  78 fn main() {}
  79
  80 fn use_mut<T>(_: &mut T) { }