kumi::identifier< ID, Checker > Struct Template Reference

identifier definition class More...

#include <kumi/utils/identifier.hpp>

Detailed Description

template<typename ID, typename Checker>
struct kumi::identifier< ID, Checker >

identifier definition class

kumi::identifier defines a identifier, i.e an entity that can receive values and can be stored as part of a product type. It is defined by a unique type ID which can be an actual type or generated from kumi::name and an optional checking operations that will validate the value passed to the identifier is acceptable.

kumi::identifier can also be used to define custom identifier type with specific behavior.

Template Parameters

ID	identifier type being defined
Checker	Potential type checker meta-function. By default, this is void to notify no check is performed.

#include <kumi/kumi.hpp>
#include <iostream>
#include <string>
 
using namespace kumi::literals;
 
inline constexpr auto name = kumi::identifier("name"_id);
 
int main()
{
  std::cout << kumi::record{ name = std::string{"Jane Doe"} } << "\n";
}

Public Types
using	tag_type = identifier<ID, Checker>
	Derived identifier type.

Public Member Functions
constexpr	identifier () noexcept
	Default constructor.
constexpr	identifier (ID const &id, Checker const &chk) noexcept
	Constructs a identifier from an ID and a checker type.
template<typename T>
constexpr field< tag_type, std::unwrap_ref_decay_t< T > >	operator= (T &&v) const noexcept
	Assignment of a value to a identifier.

Friends
constexpr str	to_str (identifier< ID, Checker > const &)
	A checked field str representation is the underlying type, checker is ignored.

Related Symbols
(Note that these are not member symbols.)
template<typename CharT, typename Traits>
std::basic_ostream< CharT, Traits > &	operator<< (std::basic_ostream< CharT, Traits > &os, identifier const &id) noexcept
	Output stream insertion.