Include Path Directory

Question

I'm somewhat confused on how to add header files to C++ projects. Often times when I attempt to use a #include "genericheader.h", it says that the file can not be found. However, the file generally exists, it's simply that the path is not written correctly So my question, by using the #include "genericheader.h", where does the compiler look for this file? Does it look in the current directory of the file that is trying to include it? Or is it dependent on things such as the IDE?

If I'm trying to include a header file, is it generally best practice to have it placed within the directory of the current file trying to include it?

Apologies for the noobish question. Thanks!

Answer 1

You are using quoted form of include directive, it searches for include files in this order:

1. In the same directory as the file that contains the #include statement.
2. In the directories of the currently opened include files, in the reverse order in which they were opened. The search begins in the directory of the parent include file and continues upward through the directories of any grandparent include files.
3. Along the path that's specified by each /I compiler option.
4. Along the paths that are specified by the INCLUDE environment variable.

Further reading: https://msdn.microsoft.com/en-us/library/36k2cdd4.aspx