Pointer type inference fails with 'unconstrained type' error

[bnoordhuis]

$ cat t.rs 
struct A<T> { inner: *T }
struct B;

fn main() {
    // works
    let _: A<B> = A::<B> { inner: std::ptr::null() };
    // works
    let _ = A::<B> { inner: std::ptr::null::<B>() };
    // cannot determine a type for this local variable: unconstrained type
    let _ = A::<B> { inner: std::ptr::null() };
}

$ rustc -v
rustc 0.11.0-pre (3a9228b 2014-06-12 19:36:53 +0000)
host: x86_64-unknown-linux-gnu

$ rustc t.rs 
t.rs:10:9: 10:47 error: cannot determine a type for this local variable: unconstrained type
t.rs:10     let _ = A::<B> { inner: std::ptr::null() };
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
error: aborting due to previous error

The third assignment seems unambiguous but the compiler won't accept it.

[alexcrichton]

This is very related to, if possibly a dupe, of #9620

[ghost]

All good now and #9620 included a test so we can close this.

[alexcrichton]

Always with the sharp eye @jakub-, thanks!