Editing Microsoft Visual C++ (section)

==== POSIX ====
Although Microsoft's CRT implements a large subset of [[POSIX]] interfaces, the Visual C++ compiler will emit a warning on ''every'' use of such functions by default. The rationale is that C and C++ standards require an underscore prefix before implementation-defined interfaces, so the use of these functions are non-standard.<ref>{{cite web |title=Compatibility |url=https://docs.microsoft.com/en-us/cpp/c-runtime-library/compatibility |website=Microsoft: CRT library features |date=26 October 2022 |language=en-us}}</ref> However, systems that are actually POSIX-compliant would not accept these underscored names, and it is more portable to just turn off the warning instead.