| #![feature(impl_trait_in_fn_trait_return)] |
| use std::fmt::Debug; |
| |
| fn fine(x: impl Into<u32>) -> impl Into<u32> { x } |
| |
| fn bad_in_ret_position(x: impl Into<u32>) -> impl Into<impl Debug> { x } |
| //~^ ERROR nested `impl Trait` is not allowed |
| //~| ERROR the trait bound `impl Debug: From<impl Into<u32>>` is not satisfied |
| |
| fn bad_in_fn_syntax(x: fn() -> impl Into<impl Debug>) {} |
| //~^ ERROR nested `impl Trait` is not allowed |
| //~| `impl Trait` only allowed in function and inherent method return types |
| |
| fn bad_in_arg_position(_: impl Into<impl Debug>) { } |
| //~^ ERROR nested `impl Trait` is not allowed |
| |
| struct X; |
| impl X { |
| fn bad(x: impl Into<u32>) -> impl Into<impl Debug> { x } |
| //~^ ERROR nested `impl Trait` is not allowed |
| //~| ERROR the trait bound `impl Debug: From<impl Into<u32>>` is not satisfied |
| } |
| |
| fn allowed_in_assoc_type() -> impl Iterator<Item=impl Fn()> { |
| vec![|| println!("woot")].into_iter() |
| } |
| |
| fn allowed_in_ret_type() -> impl Fn() -> impl Into<u32> { |
| || 5u8 |
| } |
| |
| fn main() {} |
