[Bug c++/53965] Member class initialization doesn't work with unordered_set

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53965

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-07-15 
00:29:38 UTC ---
The code is not valid, in-class initializers must use a
"brace-or-equals-initializer" meaning:

  A a{ init };

or:

  A a = init;

not:

  A a( init );