std::is_convertible

From cppreference.com

Defined in header `<type_traits>`

template< class From, class To > struct is_convertible;		(since C++11)

If an imaginary rvalue of type From can be used in the return statement of a function returning To, that is, if it can be converted to To using implicit conversion, provides the member constant value equal to true. Otherwise value is false.

Inherited from std::integral_constant

Member constants


value [static]	true if `From` is convertible to `To` , false otherwise (public static member constant)

Member functions


operator bool	converts the object to bool, returns `value` (public member function)

Member types


Type	Definition

`value_type`	`bool`

`type`	std::integral_constant<bool, value>

[edit] Notes

Gives well-defined results for reference types, void types, array types, and function types.

[edit] Example

run this code

#include <iostream>
#include <type_traits>
 
int main() 
{
    class A {};
    class B : public A {};
    class C {};
 
    bool b2a = std::is_convertible<B*, A*>::value;
    bool a2b = std::is_convertible<A*, B*>::value;
    bool b2c = std::is_convertible<B*, C*>::value;
 
    std::cout << std::boolalpha;
    std::cout << b2a << '\n';
    std::cout << a2b << '\n';
    std::cout << b2c << '\n';
}

Output:

true
false
false

Language
Standard library headers
Concepts
Utilities library
Strings library
Containers library
Algorithms library
Iterators library
Numerics library
Input/output library
Localizations library
Regular expressions library (C++11)
Atomic operations library (C++11)
Thread support library (C++11)