_SCL_SECURE_NO_WARNINGS
Calling any of the potentially unsafe methods in the C++ Standard Library results in Compiler Warning (level 3) C4996. To disable this warning, define the macro _SCL_SECURE_NO_WARNINGS in your code:
#define _SCL_SECURE_NO_WARNINGS
If you use precompiled headers, put this directive in your precompiled header file before you include any C runtime library or standard library headers. If you put it in an individual source code file before you include the precompiled header file, it is ignored by the compiler.
Remarks
Other ways to disable warning C4996 include:
Using the /D (Preprocessor Definitions) compiler option:
cl /D_SCL_SECURE_NO_WARNINGS [other compiler options] myfile.cpp
Using the /w compiler option:
cl /wd4996 [other compiler options] myfile.cpp
Using the #pragma warning directive:
#pragma warning(disable:4996)
Also, you can manually change the level of warning C4996 with the /w<l><n> compiler option. For example, to set warning C4996 to level 4:
cl /w44996 [other compiler options] myfile.cpp
For more information, see /w, /W0, /W1, /W2, /W3, /W4, /w1, /w2, /w3, /w4, /Wall, /wd, /we, /wo, /Wv, /WX (Warning Level).