How to enable C++11 in Qt Creator ?

The best solution :

 CONFIG += c++11

Add the .pro  file (see at the bottom of that web page). It requires Qt 5.

The following answer is:

QMAKE_CXXFLAGS += -std=c++11 (or QMAKE_CXXFLAGS += -std=c++0x)

Its work with Qt 4.8 and gcc / clang.
 

Set this .pro file

QMAKE_CXXFLAGS += -std=c++11

or

CONFIG += c++11

Alternative for handling both cases,

# With C++11 support
greaterThan(QT_MAJOR_VERSION, 4){
CONFIG += c++11
} else {
QMAKE_CXXFLAGS += -std=c++0x
}

The  project files  can be handle  which Qt version if people using in the team, but want them to have C++11 enabled in any case.