Search⌘ K
AI Features
Home
Courses
C++ Template Metaprogramming

Exploring the Standard Type Traits: Part 2

Explore how to use C++ standard type traits to modify cv-qualifiers, references, and pointers at compile-time. Understand the role of metafunctions like std::decay and std::conditional, and learn to simplify template code by applying these transformations effectively. This lesson enhances your ability to write flexible and robust template-based functions.

We'll cover the following...

Modifying cv-specifiers, references, pointers, or a sign

The type traits that are performing transformations on types are also called metafunctions. These type traits provided a member type (typedef) called type that represents the transformed type. This category of type traits includes the following:

Type Traits for Certain Transformations

Name

Description

add_cv

add_const

add_volatile

Add the const, volatile, or both specifiers to a type.

remove_cv

remove_const

remove_volatile

Remove the const, volatile, or both specifiers from a type.

add_value_reference

add_rvalue_reference

Add an Ivalue or value reference to a type.

remove_reference

Removes a reference (either value or rvalue) from a type.

remove_cvref

Removes the const and volatile specifiers as well as value or value references from a type. It combines the remove_cv and remove_reference traits.

add_pointer

Adds a pointer to a type.

remove_pointer

Removes a pointer from a type.

make_signed

make_unsigned

Make an integral type (except for bool) or an enumeration type either signed or unsigned. The supported integral types are short, int, long, long long, char, whar_t, char8_t, char16_t, and char32_t.

remove_extent

remove_all_extents

Remove one or all extents from an array type.

With the exception of remove_cvref, which was added in C++20, all the other type traits listed in this table are available in C++11. These aren’t all the metafunctions from the standard library. More are listed next.

Miscellaneous transformations

Apart from the metafunctions previously listed, there are other type traits performing type ...