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// edition:2018
#![allow(dead_code)]
use std::future::Future;
use std::pin::Pin;
type BoxFuture<'a, T> = Pin<Box<dyn Future<Output = T> + Send + 'a>>;
// ^^^^^^^^^ This would come from the `futures` crate in real code.
fn foo<F: Future<Output=i32> + Send + 'static>(x: F) -> BoxFuture<'static, i32> {
// We could instead use an `async` block, but this way we have no std spans.
x //~ ERROR mismatched types
}
fn bar<F: Future<Output=i32> + Send + 'static>(x: F) -> BoxFuture<'static, i32> {
Box::new(x) //~ ERROR mismatched types
}
fn baz<F: Future<Output=i32> + Send + 'static>(x: F) -> BoxFuture<'static, i32> {
Pin::new(x) //~ ERROR mismatched types
//~^ ERROR E0277
}
fn qux<F: Future<Output=i32> + Send + 'static>(x: F) -> BoxFuture<'static, i32> {
Pin::new(Box::new(x)) //~ ERROR E0277
}
fn zap() -> BoxFuture<'static, i32> {
async { //~ ERROR mismatched types
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}
}
fn main() {}
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