mirror of https://github.com/rust-lang/rust
37 lines
1017 B
Rust
37 lines
1017 B
Rust
// Test that we invoking `foo()` successfully resolves to the trait `Foo`
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// (prompting the mismatched types error) but does not influence the choice
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// of what kind of `Vec` we have, eventually leading to a type error.
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trait Foo {
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fn foo(&self) -> isize;
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}
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impl Foo for Vec<usize> {
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fn foo(&self) -> isize {1}
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}
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impl Foo for Vec<isize> {
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fn foo(&self) -> isize {2}
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}
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// This is very hokey: we have heuristics to suppress messages about
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// type annotations needed. But placing these two bits of code into
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// distinct functions, in this order, causes us to print out both
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// errors I'd like to see.
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fn m1() {
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// we couldn't infer the type of the vector just based on calling foo()...
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let mut x = Vec::new();
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//~^ ERROR type annotations needed
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x.foo(); //~ ERROR type annotations needed
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}
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fn m2() {
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let mut x = Vec::new();
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// ...but we still resolved `foo()` to the trait and hence know the return type.
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let y: usize = x.foo(); //~ ERROR mismatched types
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}
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fn main() { }
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