Please don't unconditionally define _CRT_SECURE_NO_WARNINGS

[jonesmz]

Here:

regex/src/wide_posix_api.cpp

Line 19 in ed6ebbd

#define _CRT_SECURE_NO_WARNINGS // for std::wcscpy

This introduces a warning in any project that defines this macro globally.

Better is to do

#ifndef  _CRT_SECURE_NO_WARNINGS
#define  _CRT_SECURE_NO_WARNINGS
#endif 

so that if it's already defined, it won't be re-defined.

This impacted me when i tried out the boost 1.90 beta.