Mac Forum / Programming / CodeWarrior / August 2004

// A classic test class:
class A
{
  public:
  A(char const*);
};

// A class with a dodgy interface:
class B
{
  public:
  void f(A const&)
  {
  }
  void f(bool)
  {
  }
};

void test()
{
  B b;
  b.f("");
}

b.f("") will call B::f(bool).
Note that declaring A(char const*) explicit makes no difference. Evidently,
the compiler chooses the build in convertion first anyway.

MS VC7 will output a warning:
  warning C4800: 'char *' : forcing value to bool 'true' or 'false'
(performance warning)

My colleges and I mostly turn a blind eye as soon as we see "(performance
warning)". In this particular case, I'd rather get a more meaningfull
warning e.g: "Are you sure you want us to do this?". "us" because I reckon
there has been more than 1 programmer coding the compiler...
I realize that most of the problem lies with the bool parameter since just
about anything on the face of this earth can be converted to a bool. The
example above is minimalistic. In our real code, we have bool IN-params all
over the place and many have default values which makes it all the worse.

So, just a wish!
Cheers,
Conrad Weyns