I think C++ is really powerful, read the following

[Sky89]

Hello...

I think C++ is really powerful, read the following:

I have said before that C++ allows some "implicit" conversions
and that is not good, but i have learned more C++ and now i
am understanding it more, and i think C++ is really powerful !
because you can "control" implicit conversiosn(that means disallowing
implicit conversions) by doing the following in C++, look carefully at
the following C++ code that you can extend:


===

include <iostream>
#include <stdexcept>

struct controlled_int {
// allow creation from int
controlled_int(int x) : value_(x) { };
controlled_int& operator=(int x) { value_ = x; return *this; };
// disallow assignment from bool; you might want to use
BOOST_STATIC_ASSERT instead
controlled_int& operator=(bool b) { std::cout << "Exception: Invalid
assignment of bool to controlled_int" << std::endl;
throw; return *this; };

// creation from bool shouldn't happen silently
explicit controlled_int(bool b) : value_(b) { };

// conversion to int is allowed
operator int() { return value_; };

// conversion to bool errors out; you might want to use
BOOST_STATIC_ASSERT instead

operator bool() { std::cout << "Invalid conversion of controlled_int
to bool" << std::endl;
// throw std::logic_error("Exception: Invalid conversion of
controlled_int //to bool");
};

private:
int value_;
};

int main()
{
controlled_int a(42);

// This errors out:
// bool b = a;
// This gives an error as well:
a = true;

std::cout << "Size of controlled_int: " << sizeof(a) << std::endl;
std::cout << "Size of int: " << sizeof(int) << std::endl;

return 0;
}


===