Qt – INCLUDEPATH in qmake project file doesn’t work

qmakeqtqt-creator

I've got a problem with include in a qmake project. In my .pro file I've got:

INCLUDEPATH += "C:\OpenCV\build\include"

and in my cpp :

#include <opencv\cv.h>

The compiler indicates an error:

Cannot open include file: 'opencv\cv.h': No such file or directory

but if I write this in my cpp:

#include "C:\OpenCV\build\include\opencv\cv.h"

it works!

I build the project from within Qt Creator. What am I doing wrong?

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

It's O(n) in this case (array is used), it cannot be faster.

If you just want to make the code cleaner:

 return !Collections.disjoint(group, Arrays.asList(elements));