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//@ check-pass
#![allow(dead_code)]
// Regression test for issue #21245. Check that we are able to infer
// the types in these examples correctly. It used to be that
// insufficient type propagation caused the type of the iterator to be
// incorrectly unified with the `*const` type to which it is coerced.
use std::ptr;
trait IntoIterator {
type Iter: Iterator;
fn into_iter2(self) -> Self::Iter;
}
impl<I> IntoIterator for I where I: Iterator {
type Iter = I;
fn into_iter2(self) -> I {
self
}
}
fn desugared_for_loop_bad<T>(v: Vec<T>) {
match IntoIterator::into_iter2(v.iter()) {
mut iter => {
loop {
match ::std::iter::Iterator::next(&mut iter) {
::std::option::Option::Some(x) => {
unsafe { ptr::read(x); }
},
::std::option::Option::None => break
}
}
}
}
}
fn desugared_for_loop_good<T>(v: Vec<T>) {
match v.iter().into_iter() {
mut iter => {
loop {
match ::std::iter::Iterator::next(&mut iter) {
::std::option::Option::Some(x) => {
unsafe { ptr::read(x); }
},
::std::option::Option::None => break
}
}
}
}
}
fn main() {}
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