I was playing with c++11/14 in a project created using Qt Creator. I found that Qt creator is passing -std=gnu++0x to compiler whereas my .pro file was configured to use c++11.
My <qt_project>.pro file was having:
CONFIG += c++11
The fix for this problem was to force Qt creator to use specified c++ standard instead of using default one. This can be done by having strict_c++ keyword in .pro file.
CONFIG += strict_c++ c++11