You can have a global variable or a static
class member.
1) static
class member
//BeforeMain.h
class BeforeMain
{
static bool foo;
};
//BeforeMain.cpp
#include "BeforeMain.h"
bool BeforeMain::foo = foo();
2) global variable
bool b = foo();
int main()
{
}
Note this link – Mirror of http://www.parashift.com/c++-faq-lite/ctors.html#faq-10.14 / proposed alternative – posted by Lundin.