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//@ compile-flags: -Znext-solver
// Demonstrates what's needed to make use of `?` in const contexts.
#![crate_type = "lib"]
#![feature(try_trait_v2)]
#![feature(const_trait_impl)]
#![feature(const_try)]
use std::ops::{ControlFlow, FromResidual, Try};
struct TryMe;
struct Error;
impl const FromResidual<Error> for TryMe {
//~^ ERROR const `impl` for trait `FromResidual` which is not marked with `#[const_trait]`
fn from_residual(residual: Error) -> Self {
TryMe
}
}
impl const Try for TryMe {
//~^ ERROR const `impl` for trait `Try` which is not marked with `#[const_trait]`
type Output = ();
type Residual = Error;
fn from_output(output: Self::Output) -> Self {
TryMe
}
fn branch(self) -> ControlFlow<Self::Residual, Self::Output> {
ControlFlow::Break(Error)
}
}
const fn t() -> TryMe {
TryMe?;
//~^ ERROR `?` is not allowed on
//~| ERROR `?` is not allowed on
TryMe
}
const _: () = {
t();
};
|
