std::is_convertible
From cppreference.com
Template:cpp/types/sidebar Template:ddcl list begin <tr class="t-dsc-header">
<td>Defined in header
</td>
<type_traits>
<td></td> <td></td> </tr> <tr class="t-dcl ">
<td >template< class From, class To >
struct is_convertible;
</td>
struct is_convertible;
<td class="t-dcl-nopad"> </td> <td > (since C++11) </td> </tr> Template:ddcl list end
If an imaginary rvalue of type From
can 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 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) |
operator() (C++14) |
returns value (public member function) |
Member types
Type | Definition |
value_type
|
bool |
type
|
std::integral_constant<bool, value> |
Notes
Gives well-defined results for reference types, void types, array types, and function types.
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