mirror of https://github.com/rust-lang/rust
81 lines
1.6 KiB
Rust
81 lines
1.6 KiB
Rust
#![feature(fn_traits, unboxed_closures)]
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use std::ops::{Fn, FnMut, FnOnce};
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struct SFn {
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x: isize,
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y: isize,
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}
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impl Fn<(isize,)> for SFn {
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extern "rust-call" fn call(&self, (z,): (isize,)) -> isize {
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self.x * self.y * z
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}
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}
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impl FnMut<(isize,)> for SFn {
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extern "rust-call" fn call_mut(&mut self, args: (isize,)) -> isize { self.call(args) }
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}
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impl FnOnce<(isize,)> for SFn {
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type Output = isize;
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extern "rust-call" fn call_once(self, args: (isize,)) -> isize { self.call(args) }
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}
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struct SFnMut {
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x: isize,
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y: isize,
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}
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impl FnMut<(isize,)> for SFnMut {
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extern "rust-call" fn call_mut(&mut self, (z,): (isize,)) -> isize {
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self.x * self.y * z
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}
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}
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impl FnOnce<(isize,)> for SFnMut {
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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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struct SFnOnce {
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x: String,
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}
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impl FnOnce<(String,)> for SFnOnce {
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type Output = usize;
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extern "rust-call" fn call_once(self, (z,): (String,)) -> usize {
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self.x.len() + z.len()
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}
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}
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fn f() {
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let mut s = SFn {
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x: 1,
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y: 2,
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};
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let sp = &mut s;
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s(3); //~ ERROR cannot borrow `s` as immutable because it is also borrowed as mutable
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use_mut(sp);
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}
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fn g() {
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let s = SFnMut {
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x: 1,
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y: 2,
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};
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s(3); //~ ERROR cannot borrow `s` as mutable, as it is not declared as mutable
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}
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fn h() {
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let s = SFnOnce {
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x: "hello".to_string(),
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};
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s(" world".to_string());
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s(" world".to_string()); //~ ERROR use of moved value: `s`
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}
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fn main() {}
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fn use_mut<T>(_: &mut T) { }
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