SiCrane - I don't think it's true.
GCC (also Visual Studio) defines NULL like this: "#define NULL ((void *)0)" in stddef.h.
So:

c:\ test>type a.cpp

#define NULL ((void*)0)
void foo(int);
void foo(void*);
int main()
{
  foo(NULL);
}

c:\ test>g++ a.cpp
C:\Users\XXX\AppData\Local\Temp\ccAUKoxR.o:a.cpp:(.text+0x16): undefined reference to `foo(void*)'
collect2.exe: error: ld returned 1 exit status

foo(NULL) correctly calls foo(void*).

SiCrane - I don't think it's true.
GCC (also Visual Studio) defines NULL like this: "#define NULL ((void *)0)" in stddef.h.
So:

c:\	est>type a.cpp

#define NULL ((void*)0)
void foo(int);
void foo(void*);
int main()
{
  foo(NULL);
}

c:\	est>g++ a.cpp
C:\Users\XXX\AppData\Local\Temp\ccAUKoxR.o:a.cpp:(.text+0x16): undefined reference to `foo(void*)'
collect2.exe: error: ld returned 1 exit status

foo(NULL) correctly calls foo(void*).

SiCrane - I don't think it's true.
GCC defines NULL like this: "#define NULL ((void *)0)"
So:

c:\\test>type a.cpp

#define NULL ((void*)0)
void foo(int);
void foo(void*);
int main()
{
  foo(NULL);
}

c:\\test>g++ a.cpp
C:\Users\XXX\AppData\Local\Temp\ccAUKoxR.o:a.cpp:(.text+0x16): undefined reference to `foo(void*)'
collect2.exe: error: ld returned 1 exit status

foo(NULL) correctly calls foo(void*).

SiCrane - I don't think it's true.
GCC defines NULL like this: "#define NULL ((void *)0)"
So:

c:\\test>type a.cpp

#define NULL ((void*)0)
void foo(int);
void foo(void*);
int main()
{
  foo(NULL);
}

c:\\test>g++ a.cpp
C:\Users\XXX\AppData\Local\Temp\ccAUKoxR.o:a.cpp:(.text+0x16): undefined reference to `foo(void*)'
collect2.exe: error: ld returned 1 exit status

SiCrane - I don't think it's true.

c:\\test>type a.cpp
#define NULL ((void*)0)
void foo(int);
void foo(void*);
int main()
{
  foo(NULL);
}
c:\\test>g++ a.cpp
C:\Users\XXX\AppData\Local\Temp\ccAUKoxR.o:a.cpp:(.text+0x16): undefined reference to `foo(void*)'
collect2.exe: error: ld returned 1 exit status

SiCrane - I don't think it's true.

c:	est>type a.cpp
#define NULL ((void*)0)
void foo(int);
void foo(void*);
int main()
{
  foo(NULL);
}
c:	est>g++ a.cpp
C:\Users\XXX\AppData\Local\Temp\ccAUKoxR.o:a.cpp:(.text+0x16): undefined reference to `foo(void*)'
collect2.exe: error: ld returned 1 exit status