meta_light.hpp File Reference

Table of Contents

• Classes
• Typedefs
• Variables
• Detailed Description
• Typedef Documentation
• DetectedOr
• DetectedType
• ExpectSame
• Variable Documentation
• kIsCharacter
• kIsInstantiationOf
• kIsInteger

Lightweight concepts. More...

#include <type_traits>
#include <userver/utils/void_t.hpp>

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Classes
struct	meta::NotDetected

Typedefs
template<template< typename... > typename Trait, typename... Args>
using	meta::DetectedType = typename impl::Detector< NotDetected, void, Trait, Args... >::type
	Produces the result type of a trait, or utils::meta::NotDetected if it's incorrect for the given template args.
template<typename Default , template< typename... > typename Trait, typename... Args>
using	meta::DetectedOr = typename impl::Detector< Default, void, Trait, Args... >::type
	Produces the result type of a trait, or Default if it's incorrect for the given template args.
template<typename T , typename U >
using	meta::ExpectSame = std::enable_if_t< std::is_same_v< T, U > >
	Helps in definitions of traits for utils::meta::kIsDetected.

Variables
template<template< typename... > typename Template, typename T >
constexpr bool	meta::kIsInstantiationOf
	Returns true if the type if an instantiation of the specified template.
template<typename T >
constexpr bool	meta::kIsCharacter
template<typename T >
constexpr bool	meta::kIsInteger

Detailed Description

Lightweight concepts.

See also

userver/utils/meta.hpp for more concepts

Definition in file meta_light.hpp.

Typedef Documentation

DetectedOr

template<typename Default , template< typename... > typename Trait, typename... Args>

using meta::DetectedOr = typedef typename impl::Detector<Default, void, Trait, Args...>::type

Produces the result type of a trait, or Default if it's incorrect for the given template args.

See also

utils::meta::kIsDetected

Definition at line 83 of file meta_light.hpp.

DetectedType

template<template< typename... > typename Trait, typename... Args>

using meta::DetectedType = typedef typename impl::Detector<NotDetected, void, Trait, Args...>::type

Produces the result type of a trait, or utils::meta::NotDetected if it's incorrect for the given template args.

See also

utils::meta::kIsDetected

Definition at line 75 of file meta_light.hpp.

ExpectSame

template<typename T , typename U >

using meta::ExpectSame = typedef std::enable_if_t<std::is_same_v<T, U> >

Helps in definitions of traits for utils::meta::kIsDetected.

Definition at line 87 of file meta_light.hpp.

Variable Documentation

kIsCharacter

template<typename T >

constexpr bool meta::kIsCharacter

inlineconstexpr

Initial value:

=
    std::is_same_v<T, char> || std::is_same_v<T, wchar_t> ||
    std::is_same_v<T, char16_t> || std::is_same_v<T, char32_t>

Returns true if the type is a fundamental character type. signed char and unsigned char are not character types.

Definition at line 97 of file meta_light.hpp.

kIsInstantiationOf

template<template< typename... > typename Template, typename T >

constexpr bool meta::kIsInstantiationOf

inlineconstexpr

Initial value:

=
    impl::IsInstantiationOf<Template, T>::value

Returns true if the type if an instantiation of the specified template.

Definition at line 91 of file meta_light.hpp.

kIsInteger

template<typename T >

constexpr bool meta::kIsInteger

inlineconstexpr

Initial value:

=
    std::is_integral_v<T> && !kIsCharacter<T> && !std::is_same_v<T, bool>

Returns true if the type is a true integer type (not *char* or bool) signed char and unsigned char are integer types

Definition at line 104 of file meta_light.hpp.