Custom Typecasts

[SixTsevN]

Hey there,
I'm interested to know how this c++ code works internally:

(int)32
// or..
(char)32
// or..
(float)32

I'm interested in this typecasting operation because,
I want to know if I can do something like this:

CustomType ctVar = (CustomType)32;

Would I have to create a class, then somehow overload an operator
to achieve this functionality?

Thanks for your time.

[Peter87]

This would work if CustomType is a class type with a non-explicit constructor taking an integer as argument.

class CustomType
{
public:
	CustomType(int);
private:
	/* private members */
};

[SixTsevN]

What do you mean by non-explicit constructor?

Do I still have to implement the constructor?
If not, how does the class know how to interpret the int data?

[LB]

Non-explicit meaning the explicit keyword was not applied to the constructor.

Yes, you have to implement the constructor.

http://coliru.stacked-crooked.com/a/d215d573a169c799

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

#include <iostream> struct MyClass { MyClass(int x) { std::cout << "x = " << x << std::endl; } }; int main() { MyClass a = 1; MyClass b (2); MyClass c {3}; MyClass (4); MyClass {5}; (MyClass)6; static_cast<MyClass>(7); }

x = 1 x = 2 x = 3 x = 4 x = 5 x = 6 x = 7

See also: http://coliru.stacked-crooked.com/a/4537930929bd67b1

[SixTsevN]

Okay cool,
Thank you very much.