Issue in Rust docs for Ty in libsyntax

[jroesch]

This isn't a big deal but the documentation is slightly out of date for the TyFixedLengthVec variant of ast::Ty.

Reference: http://doc.rust-lang.org/nightly/src/syntax/ast.rs.html#1247.

The comment should read:

/// A fixed length array (`[T; n]`)

I will fix this if I have time, otherwise it is a small tweak that someone looking to contribute could make.

cc @steveklabnik

[munds]

I've taken the liberty of fixing that comment :)

https://github.com/mund/rust/commit/d9fe33522bf12ab660803f1781a646656268e637

[steveklabnik]

@mund can you open up a pull request please?

[munds]

Yep, done!

#22845

Is this the right way to do it?