Defined in header <type_traits>
template< class T >
struct is_literal_type;
(since C++11)
(deprecated in C++17)
(removed in C++20)

(This type trait has been deprecated[1] and removed[2] as offering negligible value to generic code.).

If T satisfies all requirements of LiteralType, provides the member constant value equal true. For any other type, value is false.

The behavior is undefined if std::remove_all_extents_t<T> is an incomplete type and not (possibly cv-qualified) void.

The behavior of a program that adds specializations for is_literal_type or is_literal_type_v (since C++17) is undefined.

Template parameters

T - a type to check

Helper variable template

template< class T >
inline constexpr bool is_literal_type_v = is_literal_type<T>::value;
(since C++17)
(removed in C++20)

Inherited from std::integral_constant

Member constants

true if T is a literal type, false otherwise
(public static member constant)

Member functions

operator bool
converts the object to bool, returns value
(public member function)
returns value
(public member function)

Member types

Type Definition
value_type bool
type std::integral_constant<bool, value>


Only literal types may be used as parameters to or returned from constexpr functions. Only literal classes may have constexpr member functions.


#include <iostream>
#include <type_traits>
struct A
    int m;
struct B
    virtual ~B();
int main()
    std::cout << std::boolalpha;
    std::cout << std::is_literal_type<A>::value << '\n';
    std::cout << std::is_literal_type<B>::value << '\n';


  1. Alisdair Meredith. "Deprecate the is_literal Trait". Deprecating Vestigial Library Parts in C++17. "The is_literal type trait offers negligible value to generic code, as what is really needed is the ability to know that a specific construction would produce constant initialization."
  2. Alisdair Meredith, Stephan T. Lavavej, Tomasz Kamiński. "Deprecated type traits". Reviewing Deprecated Facilities of C++17 for C++20. "Strong recommendation: Remove the traits that can live on as zombies. [...] Toronto Review: Accept strong recommendation, strike from C++20."

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