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