Use of angle brackets around file names for include statements

[elfring]

Would you like to replace any double quotes by angle brackets around file names for include statements?

[wisk]

Please, tell me if I'm wrong but these included headers are the part of the program (unlike modules), so isn't it ok to use double quotes instead of angle brackets?
I know these files aren't on the same location (/inc/medusa vs. /src/core), but it's the same entity.

[elfring]

I suggest to reconsider the consequences of the following wording from the section "16.2 Source file inclusion" in the standard specification for the programming language "C++".

…
The named source file is searched for in an implementation-defined manner. If this search is not supported, or if the search fails, the directive is reprocessed as if it read

#include <h-char-sequence> new-line
…

• How do you think about to avoid "a duplicated file search" here?
• Would you like to restrict the searched directories for header files of your software?