I have a general question about what is and what is not included in standard C? I have a project and the instructor says we can only use anything that was included in C99. Because I have a heay experience in C++, I often find myself questioning whether this is in C or not. For instance, is toupper() and tolower() supported in C99?
Does anyone know where a reliable reference for stuff like this? I would purchase a book if it is affordable but I dont know a good book? But I would also be happy with an online refernece.