22 lines
446 B
Rust
22 lines
446 B
Rust
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fn mk_identity<T:copy>() -> fn@(T) -> T {
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fn@(t: T) -> T { t }
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}
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fn main() {
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// type of r is fn@(X) -> X
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// for some fresh X
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let r = mk_identity();
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// @mut int <: X
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r(@mut 3);
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// @int <: X
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//
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// Note: this is really an inference failure.
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// The correct answer would be to make X
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// equal to @const int, but we are not (yet)
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// smart enough.
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r(@3); //! ERROR (values differ in mutability)
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}
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