"Found value name used as type"

Trying to compile:

struct Foo { x: int } impl Fo { fn foo() {} } fn main() {}

gives the unhelpful error:

main.rs:5:5: 5:7 error: found value name used as a type: def_mod({crate: 0, node: 13}) main:rs:5 impl Fo { ^~

A better error message would be:

error: use of undeclared type name `Fo`

Even better would be, if it could recognize the typo:

error: use of undeclared type name `Fo`. Did you mean `Foo`?

Provide feedback