Configuring the GCC compiler switches in Qt, QtCreator, and QMake

It boils down to reading the manual. Instead of using CXXFLAGS in the .pro file, you need to use QMAKE_CXXFLAGS as in:

main.cpp:

#include <cinttypes>

int main() { return 0; }

main.pro:

SOURCES += main.cpp
QMAKE_CXXFLAGS += -std=c++0x

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You should use

CONFIG += c++11

to enable C++11 compiler flags automatically.

Look for .prf files in your qt installation. I don't know where they might be on windows, but on my Linux installation they are under /opt/Qt/5.4/gcc_64/mkspecs/features.

You might want to read the qmake documentation for that:

qmake can be set up with extra configuration features that are specified in feature (.prf) files. These extra features often provide support for custom tools that are used during the build process. To add a feature to the build process, append the feature name (the stem of the feature filename) to the CONFIG variable.

You can add your own features.

Here is what I found on my system. CONFIG += name will enable the feature:

./android/android_deployment_settings.prf
./android/android.prf
./build_pass.prf
./c++11.prf
./c++14.prf
./cmake_functions.prf
./configure.prf
./create_cmake.prf
./ctest_testcase_common.prf
./ctest_testcase_installed.prf
./ctest_testcase.prf
./dbusadaptors.prf
./dbusinterfaces.prf
./declarative_debug.prf
./default_post.prf
./default_pre.prf
./designer_defines.prf
./device_config.prf
./egl.prf
./exceptions_off.prf
./exceptions.prf
./exclusive_builds_post.prf
./exclusive_builds.prf
./gcov.prf
./include_source_dir.prf
./incredibuild_xge.prf
./java.prf
./lex.prf
./link_ltcg.prf
./link_pkgconfig.prf
./ltcg.prf
./mac/default_post.prf
./mac/default_pre.prf
./mac/objective_c.prf
./mac/rez.prf
./mac/sdk.prf
./moc.prf
./no_debug_info.prf
./precompile_header.prf
./qfeatures.prf
./qlalr.prf
./qml1_module.prf
./qml1_plugin.prf
./qml_debug.prf
./qml_module.prf
./qml_plugin.prf
./qmltestcase.prf
./qpa/basicunixfontdatabase.prf
./qpa/genericunixfontdatabase.prf
./qt_android_deps.prf
./qt_app.prf
./qt_build_config.prf
./qt_build_paths.prf
./qt_common.prf
./qt_config.prf
./qt_docs.prf
./qt_docs_targets.prf
./qt_example_installs.prf
./qt_functions.prf
./qt_headersclean.prf
./qt_helper_lib.prf
./qt_installs.prf
./qt_module_headers.prf
./qt_module.prf
./qt_module_pris.prf
./qt_parts.prf
./qt_plugin.prf
./qt.prf
./qt_targets.prf
./qt_tool.prf
./resolve_config.prf
./resolve_target.prf
./resources.prf
./silent.prf
./simd.prf
./spec_post.prf
./spec_pre.prf
./testcase.prf
./testcase_targets.prf
./testcocoon.prf
./testlib_defines.prf
./uic.prf
./unix/bsymbolic_functions.prf
./unix/dylib.prf
./unix/hide_symbols.prf
./unix/largefile.prf
./unix/opengl.prf
./unix/openvg.prf
./unix/separate_debug_info.prf
./unix/thread.prf
./unix/x11inc.prf
./unix/x11lib.prf
./unix/x11.prf
./unix/x11sm.prf
./use_c_linker.prf
./vxworks.prf
./warn_off.prf
./warn_on.prf
./wayland-scanner.prf
./win32/console.prf
./win32/default_pre.prf
./win32/dumpcpp.prf
./win32/idcidl.prf
./win32/msvc_mp.prf
./win32/opengl.prf
./win32/openvg.prf
./win32/qt_config.prf
./win32/qt_dll.prf
./win32/rtti_off.prf
./win32/rtti.prf
./win32/stl_off.prf
./win32/stl.prf
./win32/windeployqt.prf
./win32/windows.prf
./winrt/console.prf
./winrt/font_deployment.prf
./winrt/package_manifest.prf
./yacc.prf

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The only way that really works for me is to add it to QMAKE_CXXFLAGS.

The CONFIG += c++11 does not add -std=c++11 to the compile command.

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