I've seen the answer for this question here but I don't know how and where to add this code in my headers. I've tried both in my project headers and in pugixml.hpp but it doesn't work.
here is the code in the answer of previous questions:
std::string as_utf8(const char* str) { return str; }
std::wstring as_wide(const wchar_t* str) { return str; }
Thanks for your help