diff options
Diffstat (limited to 'tests/ui/methods/method-ambig-one-trait-unknown-int-type.rs')
-rw-r--r-- | tests/ui/methods/method-ambig-one-trait-unknown-int-type.rs | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/tests/ui/methods/method-ambig-one-trait-unknown-int-type.rs b/tests/ui/methods/method-ambig-one-trait-unknown-int-type.rs new file mode 100644 index 000000000..7b2fc34e1 --- /dev/null +++ b/tests/ui/methods/method-ambig-one-trait-unknown-int-type.rs @@ -0,0 +1,36 @@ +// Test that we invoking `foo()` successfully resolves to the trait `Foo` +// (prompting the mismatched types error) but does not influence the choice +// of what kind of `Vec` we have, eventually leading to a type error. + +trait Foo { + fn foo(&self) -> isize; +} + +impl Foo for Vec<usize> { + fn foo(&self) -> isize {1} +} + +impl Foo for Vec<isize> { + fn foo(&self) -> isize {2} +} + +// This is very hokey: we have heuristics to suppress messages about +// type annotations needed. But placing these two bits of code into +// distinct functions, in this order, causes us to print out both +// errors I'd like to see. + +fn m1() { + // we couldn't infer the type of the vector just based on calling foo()... + let mut x = Vec::new(); + //~^ ERROR type annotations needed + x.foo(); //~ ERROR type annotations needed +} + +fn m2() { + let mut x = Vec::new(); + + // ...but we still resolved `foo()` to the trait and hence know the return type. + let y: usize = x.foo(); //~ ERROR mismatched types +} + +fn main() { } |