mirror of https://github.com/rust-lang/rust
50 lines
950 B
Rust
50 lines
950 B
Rust
#![feature(impl_trait_in_assoc_type)]
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//@revisions: noopt opt
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//@ build-fail
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//@[noopt] compile-flags: -Copt-level=0
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//@[opt] compile-flags: -O
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//! This fails without optimizations, so it should also fail with optimizations.
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struct Fail<T>(T);
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impl<T> Fail<T> {
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const C: () = panic!(); //~ERROR evaluation of `Fail::<i32>::C` failed
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}
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#[inline(never)]
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fn not_called<T>() {
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if false {
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let _ = Fail::<T>::C;
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}
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}
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#[inline(never)]
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fn callit_not(f: impl Fn()) {
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if false {
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f();
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}
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}
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// Using `Fn` here is important; with `FnOnce` another shim gets involved which somehow makes this
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// easier to collect properly.
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trait Hideaway {
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type T: Fn();
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const C: Self::T;
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}
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impl Hideaway for () {
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type T = impl Fn();
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const C: Self::T = not_called::<i32>;
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}
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#[inline(never)]
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fn reveal<T: Hideaway>() {
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if false {
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callit_not(T::C);
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}
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}
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fn main() {
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if false {
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reveal::<()>()
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}
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}
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