[Bug c++/59056] enable_if turns a non-ambiguous template into an ambiguous one

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59056

--- Comment #1 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Needs an analysis, but I doubt this is a bug, all the up to date compilers I
have handy (eg, clang, icc) reject it the same way.