40 lines
690 B
Rust
40 lines
690 B
Rust
// Tests that a const default trait impl can be specialized by another const
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// trait impl and that the specializing impl will be used during const-eval.
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// run-pass
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#![feature(const_trait_impl, effects)]
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#![feature(min_specialization)]
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#[const_trait]
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trait Value {
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fn value() -> u32;
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}
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const fn get_value<T: ~const Value>() -> u32 {
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T::value()
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}
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impl<T> const Value for T {
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default fn value() -> u32 {
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0
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}
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}
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struct FortyTwo;
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impl const Value for FortyTwo {
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fn value() -> u32 {
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42
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}
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}
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const ZERO: u32 = get_value::<()>();
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const FORTY_TWO: u32 = get_value::<FortyTwo>();
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fn main() {
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assert_eq!(ZERO, 0);
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assert_eq!(FORTY_TWO, 42);
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}
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