Overloading on return value (with a trick)

From:
jaybus56 <busch.juergen@gmx.net>
Newsgroups:
comp.lang.c++.moderated
Date:
Wed, 24 Sep 2008 08:59:00 CST
Message-ID:
<140eadb5-824a-41b4-9bbd-b9e68cc7d0e9@l64g2000hse.googlegroups.com>
{ avoid using non-ASCII characters like '<' or '.' in your messages.
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As we know:
<.
struct TestFunky
{
  int val;
  char chr;
  TestFunky( int v, char c)
    : val(v)
    , chr(c)
  {}
};
int funky( TestFunky& v)
{
  return v.val;
}

char funky( TestFunky& v) // compiler will not accept this overload!!!
{
  return v.chr;
}
TestFunky testy( 666, 'E');
int i = funky(testy); // but we want to write it this way
char c = funky(testy); // but we want to write it this way
..>

doesn't work!

I've read a lot of (pseudo) arguments why this fact is a must. (I
disagree with (almost) all of them (as far as I remember). Anyway: it
is like it is.)

But there is a solution that solves the task (even though I don't
know, where it might make sense...):

<.
struct TestFunky
{
  int val;
  char chr;
  TestFunky( int v, char c)
    : val(v)
    , chr(c)
  {}
};
class funky
{
  TestFunky& tf_;
public:
  funky(TestFunky& tf)
      : tf_(tf)
  {}

  operator int()
  {
    return tf_.val;
  }

  operator char()
  {
    return tf_.chr;
  }
};
TestFunky testy( 666, 'E');
// and so we do as we wanted to.
int i = funky(testy);
char c = funky(testy);
// .and it even doesn't need more CPU load! (If the compiler isn't too
dumb.)
..>

Of course
<.
  funky(testy); // doesn't work
..>

but e. g.
<.
  (char)funky(testy); // works fine
..>

As I mentioned before, I don't have a good cause for that trick - just
a kind of finger exercise. ;-)

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