const_cast conversion

From Cppreference

Converts between types when no implicit conversion exists.

[edit] Syntax

All expressions return an value of type new_type.

[edit] Explanation

All above conversion operators compute the value of expression, convert it to new_type and return the resulting value. Each conversion can take place only in specific circumstances or the program is ill formed.

Casts type to an equivalent type with different cv-qualifiers.

[edit] Keywords

const_cast

[edit] Example

#include <iostream>
 
struct type {
    type()
       :i(3)
    {}
 
    void m1(int v) const 
    {
    // this->i = v; // compile error: assignment of member 'type::i' in read-only object
        const_cast<type*>(this)->i = v;
    }
 
    int i;
};
 
int main() 
{
    int i = 3;
    const int& cref_i = i;
    const_cast<int&>(cref_i) = 4;
    std::cout << "i = " << i << '\n';
 
    type t;
    t.m1(4);
 
    std::cout << "type::i = " << t.i << '\n';
}

Output:

i = 4

[edit] See also

• static_cast
• dynamic_cast
• reinterpret_cast