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      std::is_convertible

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      <tbody> </tbody>
      Definido no cabeçalho <type_traits>
      template< class From, class To > struct is_convertible;
      		 (desde C++11)
      Se um tipo de rvalue imaginário From pode usado na instrução de retorno de uma função To retorno, isto é, se ele pode ser convertido para To usando implicit conversion, fornece o membro constante igual a value true. Caso contrário value é false.
      Original:
      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.
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      Herdado de std::integral_constant

      Member constants

      value
      [estática]
      true se From is convertible to To , false contrário
      Original:
      true if From is convertible to To , false otherwise
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      (membro estático público constante)

      Member functions

      operator bool
      converte o objeto em bool, retorna value
      Original:
      converts the object to bool, returns value
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      (função pública membro)

      Member types

      Tipo
      Original:
      Type
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      		 Definition
      value_type bool
      type std::integral_constant<bool, value>

      Notas

      Dá bem definidas resultados para tipos de referência, tipos de vazios, tipos de matriz, e tipos de função.
      Original:
      Gives well-defined results for reference types, void types, array types, and function types.
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      Exemplo

      #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';
}

      Saída: 

      true
false
false
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