// Casting is evil.  If you use it, somebody’s done something wrong.
//
// C++ casting:
//    - dynamic_cast <new_type> (expression)
//	Convert (downcast) a base type pointer to a derived type.
//	Yields nullptr when you’re wrong.  Not needed for the other direction.
//
//    - static_cast <new_type> (expression)
//	Upcast/downcast pointers, and perform implicit conversions.
//
//    - const_cast <new_type> (expression)
//	Remove constness.
//
//    - reinterpret_cast <new_type> (expression)
//	Convert anything to anything--used by lunatics.
//
// C casting:
//	- (type) expression
//        Same as reinterpret_cast; avoided by savvy C++ programmers.
//
// Casting does not read your mind.  Consider (int) "123".

class Animal {
    virtual bool has_gills() = 0;
};

class Fish : public Animal {
    bool has_gills() { return true; }
};

int main() {
    Fish nemo;
    Animal *ap = &nemo;				    // no cast needed
    Fish *fp = dynamic_cast<Fish *>(ap);	    // Runtime error checking
    fp = static_cast <Fish *>(ap);		    // No error checking
    char *cp = const_cast<char *>("Hello");	    // const char * to char *
    double *dp = reinterpret_cast<double *>(&nemo); // Fish * to double * ??

    return !fp+!cp+!dp;				    // Way too cute.
}