44 lines
1.0 KiB
Rust
44 lines
1.0 KiB
Rust
//@ run-pass
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#![allow(dead_code)]
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#![allow(unused_variables)]
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// This is an example where the older inference algorithm failed. The
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// specifics of why it failed are somewhat, but not entirely, tailed
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// to the algorithm. Ultimately the problem is that when computing the
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// mutual supertype of both sides of the `if` it would be faced with a
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// choice of tightening bounds or unifying variables and it took the
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// wrong path. The new algorithm avoids this problem and hence this
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// example typechecks correctly.
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//@ pretty-expanded FIXME #23616
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enum ScopeChain<'a> {
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Link(Scope<'a>),
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End
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}
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type Scope<'a> = &'a ScopeChain<'a>;
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struct OuterContext;
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struct Context<'a> {
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foo: &'a OuterContext
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}
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impl<'a> Context<'a> {
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fn foo(&mut self, scope: Scope) {
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let link = if 1 < 2 {
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let l = ScopeChain::Link(scope);
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self.take_scope(&l);
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l
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} else {
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ScopeChain::Link(scope)
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};
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self.take_scope(&link);
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}
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fn take_scope(&mut self, x: Scope) {
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}
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}
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fn main() { }
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