27 lines
550 B
Rust
27 lines
550 B
Rust
// Tests that specializing trait impls must be at least as const as the default impl.
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#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
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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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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 Value for FortyTwo { //~ ERROR cannot specialize on const impl with non-const impl
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fn value() -> u32 {
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println!("You can't do that (constly)");
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42
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}
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}
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fn main() {}
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