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// Test an `exists<'a> { forall<'b> { 'a = 'b } }` pattern -- which should not compile!
//
// In particular, we test this pattern in trait solving, where it is not connected
// to any part of the source code.
fn foo<'a>() -> fn(&'a u32) {
panic!()
}
fn main() {
// Here, proving that `fn(&'a u32) <: for<'b> fn(&'b u32)`:
//
// - instantiates `'b` with a placeholder `!b`,
// - requires that `&!b u32 <: &'a u32` and hence that `!b: 'a`,
// - but we can never know this.
let _: for<'b> fn(&'b u32) = foo(); //~ ERROR mismatched types
}
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