Espaços nominais
Variantes
    Acções

      std::is_union

      Da cppreference.com
      < cpp‎ | types

      This page has been machine-translated from the English version of the wiki using Google Translate.

      The translation may contain errors and awkward wording. Hover over text to see the original version. You can help to fix errors and improve the translation. For instructions click here.

      Click here for the English version of this page

       
      C++
       
      Biblioteca de utilitários
      Digite apoio (basic types, RTTI, type traits)
      Gerenciamento de memória dinâmica
      De tratamento de erros
      Utilidades do programa
      Variadic funções
      Data e hora
      Objetos de função
      (C++11)
      (C++11)
      Os operadores relacionais
      Original:
      Relational operators
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      rel_ops::operator!=
      rel_ops::operator>
      rel_ops::operator<=
      rel_ops::operator>=
      Pares e tuplas
      Original:
      Pairs and tuples
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      (C++11)
      (C++11)
      (C++11)
      Troque, avançar e avançar
      Original:
      Swap, forward and move
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      (C++11)
      (C++11)
      (C++11)
      (C++11)
       
      Apoio a tipos
      Tipos básicos
      Original:
      Basic types
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      Tipos fundamentais
      Tipos inteiros de largura fixos(C++11)
      Limites numéricos
      Original:
      Numeric limits
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      C numérico limita interface
      Informações de tipo de tempo de execução
      Original:
      Runtime type information
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      Características de tipo
      Original:
      Type traits
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      Principais categorias de tipo
      Original:
      Primary type categories
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      (C++11)
      (C++11)
      (C++11)
      (C++11)
      is_union
      (C++11)
      (C++11)
      (C++11)
      (C++11)
      (C++11)
      (C++11)
      (C++11)
      (C++11)
      (C++11)
      Propriedades de tipo
      Original:
      Type properties
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      (C++11)
      (C++11)
      (C++11)
      (C++11)
      (C++11)
      (C++11)
      Operações apoiadas
      Original:
      Supported operations
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      (C++11)(C++11)(C++11)
      (C++11)(C++11)(C++11)
      (C++11)(C++11)(C++11)
      (C++11)(C++11)(C++11)
      (C++11)(C++11)(C++11)
      (C++11)(C++11)(C++11)
      (C++11)(C++11)(C++11)
      (C++11)(C++11)(C++11)
      (C++11)
      Relacionamentos e consultas de propriedade
      Original:
      Relationships and property queries
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      (C++11)
      (C++11)
      (C++11)
      (C++11)
      (C++11)
      (C++11)
      Tipo modificações
      Original:
      Type modifications
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      Transformações tipo
      Original:
      Type transformations
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      (C++11)
      (C++11)
      (C++11)
      (C++11)
      Digite constantes traço
      Original:
      Type trait constants
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      (C++11)
       
      Definido no cabeçalho <type_traits>
      template<class T >
      struct is_union;
      		(desde C++11)
      Se T é um tipo de união, fornece o membro constante valuetrue igual. Para qualquer outro tipo, é valuefalse.
      Original:
      If T is a union type, provides the member constant value equal true. For any other type, value is false.
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.

      Índice

      Herdado de std::integral_constant

      Member constants

      value
      [estática]
      true se T is a union type , false contrário
      Original:
      true if T is a union type , false otherwise
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.

      (membro estático público constante)

      Member functions

      operator bool
      converte o objeto em bool, retorna value
      Original:
      converts the object to bool, returns value
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.

      (função pública membro)

      Member types

      Tipo
      Original:
      Type
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      		 Definition
      value_typebool
      typestd::integral_constant<bool, value>

      [editar]Exemplo

      #include <iostream>#include <type_traits>   struct A {};   typedefunion{int a;float b;} B;   struct C { B d;};   int main(){std::cout<<std::boolalpha;std::cout<< std::is_union<A>::value<<'\n';std::cout<< std::is_union<B>::value<<'\n';std::cout<< std::is_union<C>::value<<'\n';std::cout<< std::is_union<int>::value<<'\n';}

      Saída: 

      false true false false

      [editar]Veja também

      (C++11)
      		 checks if a type is a class type (but not union type)
      (modelo de classe)[edit]
      Obtida de "https://pt.cppreference.com/mwiki/index.php?title=cpp/types/is_union&oldid=24584"
      close