rust-lang/rust — pull request #17379 by pcwalton (2014-09-18 23:27:08+00:00)
Title: libsyntax: Disallow keywords followed by `::`.

This breaks code that looked like:

mymacro!(static::foo);

... where `mymacro!` expects a path or expression. Change such macros to
not accept keywords followed by `::`.

Closes #17298.

[breaking-change]