2020-11-21 05:47:09 +00:00
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// Test that `variant_count` only gets evaluated once the type is concrete enough.
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2020-11-20 13:49:49 +00:00
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#![feature(variant_count)]
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pub struct GetVariantCount<T>(T);
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impl<T> GetVariantCount<T> {
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pub const VALUE: usize = std::mem::variant_count::<T>();
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}
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const fn check_variant_count<T>() -> bool {
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matches!(GetVariantCount::<T>::VALUE, GetVariantCount::<T>::VALUE)
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//~^ ERROR constant pattern depends on a generic parameter
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//~| ERROR constant pattern depends on a generic parameter
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}
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fn main() {
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assert!(check_variant_count::<Option<()>>());
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}
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