40 lines
713 B
Rust
40 lines
713 B
Rust
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// check-pass
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// Demonstrates what's needed to make use of `?` in const contexts.
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#![crate_type = "lib"]
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#![feature(try_trait_v2)]
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#![feature(const_trait_impl)]
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#![feature(const_try)]
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use std::ops::{ControlFlow, FromResidual, Try};
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struct TryMe;
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struct Error;
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impl const FromResidual<Error> for TryMe {
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fn from_residual(residual: Error) -> Self {
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TryMe
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}
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}
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impl const Try for TryMe {
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type Output = ();
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type Residual = Error;
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fn from_output(output: Self::Output) -> Self {
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TryMe
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}
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fn branch(self) -> ControlFlow<Self::Residual, Self::Output> {
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ControlFlow::Break(Error)
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}
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}
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const fn t() -> TryMe {
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TryMe?;
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TryMe
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}
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const _: () = {
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t();
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};
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