#include directive: relative to where?

Question

I have looked in The C++ Programming Language to try to find the answer to this. When I #include \"my_dir/my_header.hpp\" in a header, where does it look f

Answer 1

The complete search path may depend on the compiler. For Visual Studio, the documentation states that it:

(...) instructs the preprocessor to look for include files in the same directory of the file that contains the #include statement, and then in the directories of any files that include (#include) that file. The preprocessor then searches along the path specified by the /I compiler option, then along paths specified by the INCLUDE environment variable.