Q:

Is there a difference between _cdecl and __cdecl

Is there any difference in using _cdecl_ vs __cdecl (1 underscore vs 2 underscores) in function declaration?
I am using Visual Studio 2017 with standard tools that comes with it.

A:

__cdecl is the default calling convention for C and C++ programs used by Microsoft  Compiler. 
In fact, all of its calling conventions follow the same pattern of double underscore before the name. 
_cdecl_ seems to be just another name for __cdecl defined using a macro.

