How to use C++11 in your Qt Projects

At this moment (February 2015) qmake supports enabling C++11 (and now C++14) support via the CONFIG option in your .pro file. According to the qmake 3.0 manual that comes with Qt 5.4.0 (qmake reference) you just need to add

CONFIG += c++11

or

CONFIG += c++14

C++11 support is enabled. This option has no effect if the compiler does not support C++11. By default, support is disabled.