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.
| Contents | 
Inherited from std::integral_constant
Member constants
| value [static] | true if Fromis convertible toTo, 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


