//@ reference: destructors.scope.lifetime-extension.exprs fn temp() -> String { String::from("Hello") } #[derive(Debug)] struct X<'a>(&'a String); trait T<'a> { const A: X<'a>; const B: X<'a>; } impl<'a> T<'a> for X<'a> { // Check both Self() and X() syntax: const A: X<'a> = Self(&String::new()); const B: X<'a> = X(&String::new()); } fn main() { let a = &temp(); let b = Some(&temp()); let c = Option::Some::<&String>(&temp()); use std::option::Option::Some as S; let d = S(&temp()); let e = X(&temp()); let f = Some(Ok::<_, ()>(std::borrow::Cow::Borrowed(if true { &temp() } else { panic!() }))); let some = Some; // Turn the ctor into a regular function. let g = some(&temp()); //~ERROR temporary value dropped while borrowed println!("{a:?} {b:?} {c:?} {d:?} {e:?} {f:?} {g:?}"); }