Stringify a define
If you would like to pass a string into a define via the compiler -D directive, but need to use it as if it was a quoted #define, it takes a pair of macros (verified to work on g++ and also Visual Studio):
#define STRINGIFY_IMPL(S) #S #define STRINGIFY(s) STRINGIFY_IMPL(s)
then it can be used like this:
QFile uiFile(":" STRINGIFY(UI_FILE));
and in the .pro file if using Qt:
DEFINES += UI_FILE="some.ui"
so when it's compiled:
g++ foo.cpp -DUI_FILE=some.ui ...
(oh noes, it's DUI!)