告诉QSTE-STD= C++ 17。已覆盖qmake_cxflags

-std=C++17 .

#CONFIG += c++14 #makes -std=gnu++1y 
#CONFIG += c++17  # is not supported by Qt591
QMAKE_CXXFLAGS += -std=c++17
TARGET = equipment
TEMPLATE = app
SOURCES += ....
....

编译说明:

g++ -c -pipe -std=c++17 -g -std=gnu++11 -Wall -W -D_REENTRANT -fPIC
-DQT_DEPRECATED_WARNINGS -DQT_QML_DEBUG -DQT_SERIALPORT_LIB -DQT_CORE_LIB  
-I../app -I/opt/Qt5.9.1/5.9.1/gcc_64/include -I/opt/Qt5.9.1/5.9.1/gcc_64
/include/QtCore -I. -I/opt/Qt5.9.1/5.9.1/gcc_64/mkspecs/linux-g++ 
-o test0.o ../test0.cc

-std= -std=gnu++11 -std=c++17

- STD=C++ 17