问题
I\'m developing a program in Qt. Its makefile is generated automatically from the .pro file. I need to use some code which need the -std=c++11 flag to be set up for g++. Where in .pro should I add this flag? (changing only the Makefile won\'t work since it gets overwritten by the newly generated one, each time I build the project).
回答1:
You may find it tempting to insert the specific flag (which you mention)
QMAKE_CXXFLAGS += -std=c++11
in your .pro file, but this will insert just that flag on your behalf.
That's insufficient. The right way is to insert instead
CONFIG += c++11
in your .pro file. Two or three necessary changes are then made by qmake:
-std=c++11is inserted.-stdlib=libc++is inserted.- If you're on a Mac,
-mmacosx-version-min=10.6becomes-mmacosx-version-min=10.7. (Perhaps some similar change is necessary on other OSes or OS versions.)
(A similar issue at 1 and 2.)
回答2:
You can add the following to the Qt .pro for C++11: -
CONFIG += c++11
As of Qt 5.4, C++14 can be enabled with
CONFIG += c++14
回答3:
You can change CXX flags :
QMAKE_CXXFLAGS += -std=c++11
I usually set it as :
QMAKE_CXXFLAGS += -std=c++11 -Wall -Wextra -pedantic
回答4:
I'm using Snow Leopad 10.6.8 and gcc 4.9, I had to use
CONFIG += c++11
instead of
QMAKE_CXXFLAGS += -std=c++11
The latter was simply not recognized.
回答5:
CONFIG += c++11
in .pro file appears to work for me with the Qt4 SDK after installing qt5-default on my Ubuntu desktop:
sudo apt install qt5-default
Anyway the generated makefile contains a -std=c++0x option I suspect to be sufficient to compile my C++11 code.
来源：https://stackoverflow.com/questions/19398438/c-qt-how-to-add-std-c11-to-the-makefile-which-is-generated-by-qmake