mirror of https://github.com/rust-lang/rust
16 lines
463 B
Rust
16 lines
463 B
Rust
enum Enum<T> { SVariant { v: T }, UVariant }
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macro_rules! is_variant {
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(TSVariant, ) => (!);
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(SVariant, ) => (!);
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(UVariant, $expr:expr) => (is_variant!(@check UVariant, {}, $expr));
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(@check $variant:ident, $matcher:tt, $expr:expr) => (
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assert!(if let Enum::$variant::<()> $matcher = $expr () { true } else { false },
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);
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);
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}
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fn main() {
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is_variant!(UVariant, Enum::<()>::UVariant); //~ ERROR expected function
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}
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