src/test/ui/async-await/multiple-lifetimes/variance.rs


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// edition:2018
// run-pass

// Test for async fn where the parameters have distinct lifetime
// parameters that appear in all possible variances.

async fn lotsa_lifetimes<'a, 'b, 'c>(_: fn(&'a u8), _: fn(&'b u8) -> &'b u8, _: fn() -> &'c u8) { }

fn take_any(_: &u8) { }
fn identify(x: &u8) -> &u8 { x }
fn give_back() -> &'static u8 { &22 }

fn main() {
    let _ = lotsa_lifetimes(take_any, identify, give_back);
}