| use std::marker; |
| |
| struct A; |
| struct B; |
| struct C; |
| struct Foo<T = A, U = B, V = C>(marker::PhantomData<(T,U,V)>); |
| |
| struct Hash<T>(marker::PhantomData<T>); |
| struct HashMap<K, V, H = Hash<K>>(marker::PhantomData<(K,V,H)>); |
| |
| fn main() { |
| // Ensure that the printed type doesn't include the default type params... |
| let _: Foo<isize> = (); |
| //~^ ERROR mismatched types |
| //~| expected type `Foo<isize>` |
| //~| found type `()` |
| //~| expected struct `Foo`, found () |
| |
| // ...even when they're present, but the same types as the defaults. |
| let _: Foo<isize, B, C> = (); |
| //~^ ERROR mismatched types |
| //~| expected type `Foo<isize>` |
| //~| found type `()` |
| //~| expected struct `Foo`, found () |
| |
| // Including cases where the default is using previous type params. |
| let _: HashMap<String, isize> = (); |
| //~^ ERROR mismatched types |
| //~| expected type `HashMap<std::string::String, isize>` |
| //~| found type `()` |
| //~| expected struct `HashMap`, found () |
| let _: HashMap<String, isize, Hash<String>> = (); |
| //~^ ERROR mismatched types |
| //~| expected type `HashMap<std::string::String, isize>` |
| //~| found type `()` |
| //~| expected struct `HashMap`, found () |
| |
| // But not when there's a different type in between. |
| let _: Foo<A, isize, C> = (); |
| //~^ ERROR mismatched types |
| //~| expected type `Foo<A, isize>` |
| //~| found type `()` |
| //~| expected struct `Foo`, found () |
| |
| // And don't print <> at all when there's just defaults. |
| let _: Foo<A, B, C> = (); |
| //~^ ERROR mismatched types |
| //~| expected type `Foo` |
| //~| found type `()` |
| //~| expected struct `Foo`, found () |
| } |