It's illegal in C++11: §8.3.6.4 [dcl.fct.default]
"If a friend declaration specifies a default argument expression,
that declaration shall be a definition and shall be the only declaration
of the function or function template in the translation unit."
Clang is starting to enforce this, thus it's making qtbase not compiling.
Task-number: QTBUG-32100
Change-Id: Ifd9d4f62354d7cf4ccf275f36aab64e05c59efff
Reviewed-by: Thorbjørn Lund Martsum <tmartsum@gmail.com>
Reviewed-by: Mitch Curtis <mitch.curtis@digia.com>
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
658dfef500