title: How to define UNICODE for mingw, if use CMAKE as building system
body: <p>Good day, i build my Qt project with Cmake build system on windows platform, but if i add line in cmake file: <pre>add_definitions("-DUNICODE -D_UNICODE")</pre>  definition of UNICODE not working(MINGW), this work properly only if i build my project with MSVC compiler. After some times i found workaround <a href="https://stackoverflow.com/questions/7408262/how-do-i-define-a-variable-when-i-call-cmake-so-that-qtcreator-knows-it-is-defi">How do I define a variable when I call CMake, so that qtcreator knows it is defined?</a>, this solution work but if i use native WINAPI functions such as CreateFile i get the compile error, because compiler chose CreateFileA but i use w_char and i would like to use CreateFileW, this is because the definition of macro UNICODE appears before than i include my confugure file.How can i define UNICODE macro in cmakefile?</p>