std::remove_cv, std::remove_const, std::remove_volatile
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| Elemento definito nell'header <type_traits>
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| template< class T > struct remove_cv; |
(1) | (dal C++11) |
| template< class T > struct remove_const; |
(2) | (dal C++11) |
| template< class T > struct remove_volatile; |
(3) | (dal C++11) |
Provides the member typedef type which is the same as T, except that its topmost cv-qualifiers are removed.
1) removes the topmost const, the topmost volatile, or both, if present.
2) removes the topmost const
3) removes the topmost volatile
Indice |
[modifica] Membri tipi
| Nome
Original: Name The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
Definition |
type
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the type T without cv-qualifier
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[modifica] Possibile implementazione
template< class T > struct remove_cv { typedef typename std::remove_volatile<typename std::remove_const<T>::type>::type type; }; template< class T > struct remove_const { typedef T type; }; template< class T > struct remove_const<const T> { typedef T type; }; template< class T > struct remove_volatile { typedef T type; }; template< class T > struct remove_volatile<volatile T> { typedef T type; }; |
[modifica] Esempio
Removing const/volatile from const volatile int * does not modify the type, because the pointer itself is neither const nor volatile.
#include <iostream> #include <type_traits> int main() { typedef std::remove_cv<const int>::type type1; typedef std::remove_cv<volatile int>::type type2; typedef std::remove_cv<const volatile int>::type type3; typedef std::remove_cv<const volatile int*>::type type4; typedef std::remove_cv<int * const volatile>::type type5; std::cout << "test1 " << (std::is_same<int, type1>::value ? "passed" : "failed") << '\n'; std::cout << "test2 " << (std::is_same<int, type2>::value ? "passed" : "failed") << '\n'; std::cout << "test3 " << (std::is_same<int, type3>::value ? "passed" : "failed") << '\n'; std::cout << "test4 " << (std::is_same<const volatile int*, type4>::value ? "passed" : "failed") << '\n'; std::cout << "test5 " << (std::is_same<int*, type5>::value ? "passed" : "failed") << '\n'; }
Output:
test1 passed test2 passed test3 passed test4 passed test5 passed
[modifica] Vedi anche
| (C++11) |
controlla se è un tipo const qualificati Original: checks if a type is const-qualified The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (classe template) |
| (C++11) |
controlla se è un tipo di volatili qualificato Original: checks if a type is volatile-qualified The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (classe template) |
