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#![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() {}
|
