mirror of https://github.com/rust-lang/rust
47 lines
866 B
Rust
47 lines
866 B
Rust
//@ build-pass
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// issue 122301 - currently the only way to supress
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// const eval and codegen of code conditional on some other const
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struct Foo<T, const N: usize>(T);
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impl<T, const N: usize> Foo<T, N> {
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const BAR: () = if N == 0 {
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panic!()
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};
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}
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struct Invoke<T, const N: usize>(T);
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impl<T, const N: usize> Invoke<T, N> {
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const FUN: fn() = if N != 0 {
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|| Foo::<T, N>::BAR
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} else {
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|| {}
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};
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}
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// without closures
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struct S<T>(T);
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impl<T> S<T> {
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const C: () = panic!();
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}
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const fn bar<T>() { S::<T>::C }
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struct ConstIf<T, const N: usize>(T);
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impl<T, const N: usize> ConstIf<T, N> {
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const VAL: () = if N != 0 {
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bar::<T>() // not called for N == 0, and hence not monomorphized
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} else {
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()
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};
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}
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fn main() {
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let _val = Invoke::<(), 0>::FUN();
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let _val = ConstIf::<(), 0>::VAL;
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}
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