What does "cv-unqualified" mean in C++?

As from subject. I saw this terminology in a question I recently asked, and apparently it's a well established term, but I am not able to find anything on stackoverflow.

There are fundamental types and compound types. Fundamental types are the arithmetic types, void, and std::nullptr_t. Compound types are arrays, functions, pointers, references, classes, unions, enumerations, and pointers to non-static members.

A cv-unqualified type is any of those types.

For any cv-unqualified type, there are three corresponding cv-qualified types:

• const-qualified - with the const cv-qualifier
• volatile-qualified - with the volatile cv-qualifier
• const-volatile-qualified - with both the const and volatile cv-qualifiers

Note, however, that cv-qualifiers applied to an array type actually apply to its elements.

The cv-qualified and cv-unqualified types are distinct. That is int is a distinct type from const int.

A type is "cv-unqualified" if it doesn't have any cv-qualifiers. A cv-qualifer is either const or volatile.

cv stands for const and volatile (and more rarely mutable), two attributes qualifying a type. You can manipulate them with std::remove_const and the like in C++11.

The excellent cppreference site gives you more info.

To answer your question, a cv-unqualified type either doesn't have or is stripped from its cv-qualifiers. For instance int is the cv-unqualified part of const volatile int.

std::remove_cv<T>::type is the cv-unqualified partof T.