is_const Class

 

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Tests if type is const.

template <class Ty>  
struct is_const;

Parameters

Ty
The type to query.

An instance of the type predicate holds true if Ty is const-qualified.

// std_tr1__type_traits__is_const.cpp   
// compile with: /EHsc   
#include <type_traits>   
#include <iostream>   
  
struct trivial   
    {   
    int val;   
    };   
  
int main()   
    {   
    std::cout << "is_const<trivial> == " << std::boolalpha   
        << std::is_const<trivial>::value << std::endl;   
    std::cout << "is_const<const trivial> == " << std::boolalpha   
        << std::is_const<const trivial>::value << std::endl;   
    std::cout << "is_const<int> == " << std::boolalpha   
        << std::is_const<int>::value << std::endl;   
    std::cout << "is_const<const int> == " << std::boolalpha   
        << std::is_const<const int>::value << std::endl;   
  
    return (0);   
    }  
  

is_const<trivial> == false  
is_const<const trivial> == true  
is_const<int> == false  
is_const<const int> == true  

Header: <type_traits>

Namespace: std

<type_traits>
is_volatile Class

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