std::is_pointer
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definiert in Header <type_traits> | ||
template<class T > struct is_pointer; | (seit C++11) | |
Wenn
T
ein Objekt Zeiger-oder eine Funktion Zeigertyp (aber nicht Zeiger auf nicht-statische Member-Objekt oder Member-Funktion) ist, stellt das Mitglied konstanten value
gleich true. Für jede andere Art, value
ist false .Original:
If
T
is an object pointer type or a function pointer type (but not pointer to non-static member object or member function), 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.
You can help to correct and verify the translation. Click here for instructions.
Inhaltsverzeichnis |
Inherited from std::integral_constant
Member constants
value [statisch] | true wenn T is a pointer type , false anders Original: true if T is a pointer 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. (public static Mitglied konstanten) |
Member functions
operator bool | wandelt das Objekt bool, gibt 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. (öffentliche Elementfunktion) |
Member types
Type 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_type | bool |
type | std::integral_constant<bool, value> |
[Bearbeiten]Mögliche Implementierung
template<class T >struct is_pointer_helper :std::false_type{};template<class T >struct is_pointer_helper<T*>:std::true_type{};template<class T >struct is_pointer : is_pointer_helper<typenamestd::remove_cv<T>::type>{}; |
[Bearbeiten]Beispiel
#include <iostream>#include <type_traits> class A {}; int main(){std::cout<<std::boolalpha;std::cout<< std::is_pointer<A>::value<<'\n';std::cout<< std::is_pointer<A*>::value<<'\n';std::cout<< std::is_pointer<float>::value<<'\n';std::cout<< std::is_pointer<int>::value<<'\n';std::cout<< std::is_pointer<int*>::value<<'\n';std::cout<< std::is_pointer<int**>::value<<'\n';}
Output:
false true false false true true
[Bearbeiten]Siehe auch
(C++11) | prüft, ob ein Typ ist ein Array-Typ Original: checks if a type is an array type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Klassen-Template) |
(C++11) | prüft, ob ein Typ ist skalaren Typ Original: checks if a type is scalar type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Klassen-Template) |