Why is there an implicit type conversion from pointers to bool in C++?

Question

Consider the class foo with two constructors defined like this:

class foo
{
public:
    foo(const std::string& filename) {std::cout <<         


        

Answer 1

You're passing a char* to the foo constructor. This can be implicitly converted to a boolean (as can all pointers) or to a std::string. From the compiler's point of view, the first conversion is "closer" than the second because it favours standard conversions (i.e. pointer to bool) over user provided conversions (the std::string(char*) constructor).