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// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
// This is an example where the older inference algorithm failed. The
// specifics of why it failed are somewhat, but not entirely, tailed
// to the algorithm. Ultimately the problem is that when computing the
// mutual supertype of both sides of the `if` it would be faced with a
// choice of tightening bounds or unifying variables and it took the
// wrong path. The new algorithm avoids this problem and hence this
// example typechecks correctly.
// pretty-expanded FIXME #23616
enum ScopeChain<'a> {
Link(Scope<'a>),
End
}
type Scope<'a> = &'a ScopeChain<'a>;
struct OuterContext;
struct Context<'a> {
foo: &'a OuterContext
}
impl<'a> Context<'a> {
fn foo(&mut self, scope: Scope) {
let link = if 1 < 2 {
let l = ScopeChain::Link(scope);
self.take_scope(&l);
l
} else {
ScopeChain::Link(scope)
};
self.take_scope(&link);
}
fn take_scope(&mut self, x: Scope) {
}
}
fn main() { }
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