Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!microsoft!jimad
From: jimad@microsoft.UUCP (JAMES ADCOCK)
Newsgroups: comp.lang.c++
Subject: Re: C++ masquerading as C ... How?
Message-ID: <10193@microsoft.UUCP>
Date: 9 Jan 90 18:26:10 GMT
References: <6170011@hpindda.HP.COM>
Reply-To: jimad@microsoft.UUCP (JAMES ADCOCK)
Organization: Microsoft Corp., Redmond WA
Lines: 20

Although not stated anywhere explicetly, the extern "C" construct works both
ways -- it can be used to tell a C++ program to look for a C function
of that name, but it can also be used to tell a C++ program to generate
a function of that name -- IE turn off name mangling for this one function:

#include <stdio.h>

extern "C" int foo() { return 1234; }

int foo2() { return 1234; }

main()
{
    printf("%d\n", foo() );
    printf("%d\n", foo2() );
}

On my machine, in linker land foo is known as "_foo" [ as would be a 
function written in K&R C ], whereas foo2 is known by the mangled name
"_foo__Fv"