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// Test that we consider equal regions when checking for hidden regions in
// opaque types
// check-pass
// `'a == 'static` so `&'a i32` is fine as the return type
fn equal_regions_static<'a: 'static>(x: &'a i32) -> impl Sized {
//~^ WARNING unnecessary lifetime parameter `'a`
x
}
// `'a == 'b` so `&'b i32` is fine as the return type
fn equal_regions<'a: 'b, 'b: 'a>(x: &'b i32) -> impl Sized + 'a {
let y: &'a i32 = x;
let z: &'b i32 = y;
x
}
// `'a == 'b` so `&'a i32` is fine as the return type
fn equal_regions_rev<'a: 'b, 'b: 'a>(x: &'a i32) -> impl Sized + 'b {
let y: &'a i32 = x;
let z: &'b i32 = y;
x
}
// `'a == 'b` so `*mut &'b i32` is fine as the return type
fn equal_regions_inv<'a: 'b, 'b: 'a>(x: *mut &'b i32) -> impl Sized + 'a {
let y: *mut &'a i32 = x;
let z: *mut &'b i32 = y;
x
}
// `'a == 'b` so `*mut &'a i32` is fine as the return type
fn equal_regions_inv_rev<'a: 'b, 'b: 'a>(x: *mut &'a i32) -> impl Sized + 'b {
let y: *mut &'a i32 = x;
let z: *mut &'b i32 = y;
x
}
// Should be able to infer `fn(&'static ())` as the return type.
fn contravariant_lub<'a, 'b: 'a, 'c: 'a, 'd: 'b + 'c>(
x: fn(&'b ()),
y: fn(&'c ()),
c: bool,
) -> impl Sized + 'a {
if c { x } else { y }
}
fn main() {}
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