cv-qualifier

CV stands for Constant-Volatile. The declaration of an object that is not preceded by const and/or volatile is a cv-unqualified type. On the other hand, the declaration of an object that is preceded by const and/or volatile is a cv-qualified type.

```
struct foo {
   void test()       { std::cout << "test" << std::endl; }
   void test() const { std::cout << "test const" << std::endl; }
};

foo f1;
f1.test();     // prints "test"
foo const f2;
f2.test();     // prints "test const"
foo().test();  // prints "test"
```