Can't infer the type of index

[yongqli]

This doesn't type-check

fn main() {
    let m = [[0.; 2]; 2];
    println!("{}", (|i, j| m[i][j])(0, 1));
}

failing with

error[E0282]: type annotations needed
 --> inf.rs:3:28
  |
3 |     println!("{}", (|i, j| m[i][j])(0, 1));
  |                            ^^^^ cannot infer type

Annotating as usize fixes it, but I would expect the compiler to be able to infer the type. Is there a reason why it can't?

[bluss]

See also issue #12679

[steveklabnik]

Triage: No change.

[steveklabnik]

Triage: no changes

[Spoonbender]

triage: no change