68 lines
2.0 KiB
Rust
68 lines
2.0 KiB
Rust
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// Test the enum_intrinsics_non_enums lint.
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#![feature(variant_count)]
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use std::mem::{discriminant, variant_count};
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enum SomeEnum {
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A,
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B,
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}
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struct SomeStruct;
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fn generic_discriminant<T>(v: &T) {
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discriminant::<T>(v);
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}
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fn generic_variant_count<T>() -> usize {
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variant_count::<T>()
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}
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fn test_discriminant() {
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discriminant(&SomeEnum::A);
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generic_discriminant(&SomeEnum::B);
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discriminant(&());
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//~^ error: the return value of `mem::discriminant` is unspecified when called with a non-enum type
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discriminant(&&SomeEnum::B);
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//~^ error: the return value of `mem::discriminant` is unspecified when called with a non-enum type
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discriminant(&SomeStruct);
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//~^ error: the return value of `mem::discriminant` is unspecified when called with a non-enum type
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discriminant(&123u32);
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//~^ error: the return value of `mem::discriminant` is unspecified when called with a non-enum type
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discriminant(&&123i8);
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//~^ error: the return value of `mem::discriminant` is unspecified when called with a non-enum type
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}
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fn test_variant_count() {
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variant_count::<SomeEnum>();
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generic_variant_count::<SomeEnum>();
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variant_count::<&str>();
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//~^ error: the return value of `mem::variant_count` is unspecified when called with a non-enum type
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variant_count::<*const u8>();
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//~^ error: the return value of `mem::variant_count` is unspecified when called with a non-enum type
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variant_count::<()>();
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//~^ error: the return value of `mem::variant_count` is unspecified when called with a non-enum type
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variant_count::<&SomeEnum>();
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//~^ error: the return value of `mem::variant_count` is unspecified when called with a non-enum type
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}
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fn main() {
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test_discriminant();
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test_variant_count();
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// The lint ignores cases where the type is generic, so these should be
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// allowed even though their return values are unspecified
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generic_variant_count::<SomeStruct>();
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generic_discriminant::<SomeStruct>(&SomeStruct);
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}
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