mirror of https://github.com/rust-lang/rust
30 lines
613 B
Rust
30 lines
613 B
Rust
// Checks that the Fn trait hierarchy rules do not permit
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// Fn to be used where FnMut is implemented.
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#![feature(fn_traits, unboxed_closures)]
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use std::ops::{Fn,FnMut,FnOnce};
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struct S;
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impl FnMut<(isize,)> for S {
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extern "rust-call" fn call_mut(&mut self, (x,): (isize,)) -> isize {
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x * x
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}
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}
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impl FnOnce<(isize,)> for S {
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type Output = isize;
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extern "rust-call" fn call_once(mut self, args: (isize,)) -> isize { self.call_mut(args) }
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}
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fn call_it<F:Fn(isize)->isize>(f: &F, x: isize) -> isize {
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f.call((x,))
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}
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fn main() {
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let x = call_it(&S, 22);
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//~^ ERROR E0277
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}
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