trait X { fn foo(&self) {} } fn p1<T>(v: T) -> Box<dyn X + 'static> where T : X { Box::new(v) //~ ERROR parameter type `T` may not live long enough } fn p2<T>(v: Box<T>) -> Box<dyn X + 'static> where Box<T> : X { Box::new(v) //~ ERROR parameter type `T` may not live long enough } fn p3<'a,T>(v: T) -> Box<dyn X + 'a> where T : X { Box::new(v) //~ ERROR parameter type `T` may not live long enough } fn p4<'a,T>(v: Box<T>) -> Box<dyn X + 'a> where Box<T> : X { Box::new(v) //~ ERROR parameter type `T` may not live long enough } fn main() {}