自动类型转换功能调用C ++

Question

Is there a way to automatically convert to a certain type:

class A
{ public:
  int f();
  float g();
};
r(int x){}
t(float x){}

...

r(A) //automagically call r(A.f())
t(A) //automagically call t(A,t())

sort of like when toString is called for Java objects when you print them.

Answer 1

Yes, you can provide cast operators for A .

class A
{ 
public:
  int f();
  float g();

  operator int() { return f(); }
  operator float() { return g(); }
};

But you then call r and t on an instance:

A a;
r(a);
t(a);

Here's the full code: http://ideone.com/Pfa4v