How to make preprocessor generate a string for __LINE__ keyword?

Question

__FILE__ is replaced with \"MyFile.cpp\" by C++ preprocessor. I want __LINE__ to be replaced with \"256\" string not with 256 integer. Without using m

Answer 1

EDIT: In response to request on the other answer, I added a non-macro version:

#include 
#include 
#include 

#define B(x) #x
#define A(x) B(x)

void f(const char *s) {
std::cout << s << "\n";
}

int main() {

   f(A(__LINE__));
   f(boost::lexical_cast(__LINE__).c_str());
}