gw::strong_type< T, Tag > Class Template Reference

Strong type wrapper. More...

#include <strong_type.hpp>

Inheritance diagram for gw::strong_type< T, Tag >:

Collaboration diagram for gw::strong_type< T, Tag >:

Public Types
using	value_type = T
	The type of the contained value.
using	tag_type = Tag
	The tag type.

Public Member Functions
template<typename... Args> requires std::constructible_from<value_type, Args...>
constexpr	strong_type (Args &&... args) noexcept(std::is_nothrow_constructible_v< value_type, Args... >)
	Construct the gw::strong_type object.
template<typename U , typename... Args> requires std::constructible_from<value_type, std::initializer_list<U>&, Args...>
constexpr	strong_type (std::initializer_list< U > ilist, Args &&... args) noexcept(std::is_nothrow_constructible_v< value_type, std::initializer_list< U > &, Args... >)
	constructs the gw::strong_type object
	~strong_type () noexcept(std::is_nothrow_destructible_v< value_type >)=default
	destroys the contained value
constexpr auto	operator-> () const noexcept -> const value_type *
	accesses the contained value
constexpr auto	operator-> () noexcept -> value_type *
	accesses the contained value
constexpr auto	operator* () const &noexcept -> const value_type &
	accesses the contained value
constexpr auto	operator* () &noexcept -> value_type &
	accesses the contained value
constexpr auto	operator* () const &&noexcept -> const value_type &&
	accesses the contained value
constexpr auto	operator* () &&noexcept -> value_type &&
	accesses the contained value
constexpr auto	value () const &noexcept -> const value_type &
	returns the contained value
constexpr auto	value () &noexcept -> value_type &
	returns the contained value
constexpr auto	value () const &&noexcept -> const value_type &&
	returns the contained value
constexpr auto	value () &&noexcept -> value_type &&
	returns the contained value
template<typename F > requires std::invocable<F, const value_type&>
constexpr auto	transform (F &&func) const &noexcept(noexcept(func(m_value))) -> strong_type
	returns a gw::strong_type containing the transformed contained value
template<typename F > requires std::invocable<F, value_type&>
constexpr auto	transform (F &&func) &noexcept(noexcept(func(m_value))) -> strong_type
	returns a gw::strong_type containing the transformed contained value
template<typename F > requires std::invocable<F, const value_type&&>
constexpr auto	transform (F &&func) const &&noexcept(noexcept(func(m_value))) -> strong_type
	returns a gw::strong_type containing the transformed contained value
template<typename F > requires std::invocable<F, value_type&&>
constexpr auto	transform (F &&func) &&noexcept(noexcept(func(m_value))) -> strong_type
	returns a gw::strong_type containing the transformed contained value
constexpr void	swap (strong_type &rhs) noexcept(std::is_nothrow_swappable_v< value_type >)
	specializes the std::swap algorithm
constexpr void	reset () noexcept(std::is_nothrow_default_constructible_v< value_type >)
	destroys any contained value
template<typename... Args> requires std::constructible_from<value_type, Args...>
constexpr auto	emplace (Args &&... args) noexcept(std::is_nothrow_constructible_v< value_type, Args... >) -> value_type &
	constructs the contained value in-place
constexpr auto	operator== (const strong_type &rhs) const &noexcept(noexcept(m_value==rhs.m_value)) -> bool
	compares gw::strong_type objects
constexpr auto	operator< (const strong_type &rhs) const &noexcept(noexcept(m_value< rhs.m_value)) -> bool
	compares gw::strong_type objects
constexpr auto	operator> (const strong_type &rhs) const &noexcept(noexcept(m_value > rhs.m_value)) -> bool
	compares gw::strong_type objects
constexpr	operator const value_type & () const &noexcept
	converts the gw::strong_type to its underlying type
constexpr	operator value_type & () &noexcept
	converts the gw::strong_type to its underlying type
constexpr	operator const value_type && () const &&noexcept
	converts the gw::strong_type to its underlying type
constexpr	operator value_type && () &&noexcept
	converts the gw::strong_type to its underlying type
constexpr auto	operator++ () &noexcept(noexcept(++m_value)) -> strong_type &
	increments the contained value
constexpr auto	operator++ () &&noexcept(noexcept(++m_value)) -> strong_type &&
	increments the contained value
constexpr auto	operator++ (int) &noexcept(noexcept(m_value++)) -> strong_type
	increments the contained value
constexpr auto	operator++ (int) &&noexcept(noexcept(m_value++)) -> strong_type
	increments the contained value
constexpr auto	operator-- () &noexcept(noexcept(--m_value)) -> strong_type &
	decrements the contained value
constexpr auto	operator-- () &&noexcept(noexcept(--m_value)) -> strong_type &&
	decrements the contained value
constexpr auto	operator-- (int) &noexcept(noexcept(m_value--)) -> strong_type
	decrements the contained value
constexpr auto	operator-- (int) &&noexcept(noexcept(m_value--)) -> strong_type
	decrements the contained value
constexpr auto	operator+ () const &noexcept(noexcept(+m_value)) -> strong_type
	affirms the contained value
constexpr auto	operator+ () &&noexcept(noexcept(+m_value)) -> strong_type
	affirms the contained value
constexpr auto	operator- () const &noexcept(noexcept(-m_value)) -> strong_type
	negates the contained value
constexpr auto	operator- () &&noexcept(noexcept(-m_value)) -> strong_type
	negates the contained value
constexpr auto	operator+ (const strong_type &rhs) const &noexcept(noexcept(m_value+rhs.m_value)) -> strong_type
	adds the contained values
constexpr auto	operator+ (strong_type &&rhs) const &noexcept(noexcept(m_value+rhs.m_value)) -> strong_type
	adds the contained values
constexpr auto	operator+ (const strong_type &rhs) &&noexcept(noexcept(m_value+rhs.m_value)) -> strong_type
	adds the contained values
constexpr auto	operator+ (strong_type &&rhs) &&noexcept(noexcept(m_value+rhs.m_value)) -> strong_type
	adds the contained values
constexpr auto	operator- (const strong_type &rhs) const &noexcept(noexcept(m_value - rhs.m_value)) -> strong_type
	subtracts the contained values
constexpr auto	operator- (strong_type &&rhs) const &noexcept(noexcept(m_value - rhs.m_value)) -> strong_type
	subtracts the contained values
constexpr auto	operator- (const strong_type &rhs) &&noexcept(noexcept(m_value - rhs.m_value)) -> strong_type
	subtracts the contained values
constexpr auto	operator- (strong_type &&rhs) &&noexcept(noexcept(m_value - rhs.m_value)) -> strong_type
	subtracts the contained values
constexpr auto	operator* (const strong_type &rhs) const &noexcept(noexcept(m_value *rhs.m_value)) -> strong_type
	multiplies the contained values
constexpr auto	operator* (strong_type &&rhs) const &noexcept(noexcept(m_value *rhs.m_value)) -> strong_type
	multiplies the contained values
constexpr auto	operator* (const strong_type &rhs) &&noexcept(noexcept(m_value *rhs.m_value)) -> strong_type
	multiplies the contained values
constexpr auto	operator* (strong_type &&rhs) &&noexcept(noexcept(m_value *rhs.m_value)) -> strong_type
	multiplies the contained values
constexpr auto	operator/ (const strong_type &rhs) const &noexcept(noexcept(m_value/rhs.m_value)) -> strong_type
	devides the contained values
constexpr auto	operator/ (strong_type &&rhs) const &noexcept(noexcept(m_value/rhs.m_value)) -> strong_type
	devides the contained values
constexpr auto	operator/ (const strong_type &rhs) &&noexcept(noexcept(m_value/rhs.m_value)) -> strong_type
	devides the contained values
constexpr auto	operator/ (strong_type &&rhs) &&noexcept(noexcept(m_value/rhs.m_value)) -> strong_type
	devides the contained values
constexpr auto	operator% (const strong_type &rhs) const &noexcept(noexcept(m_value % rhs.m_value)) -> strong_type
	calculates the remainder of the contained values
constexpr auto	operator% (strong_type &&rhs) const &noexcept(noexcept(m_value % rhs.m_value)) -> strong_type
	calculates the remainder of the contained values
constexpr auto	operator% (const strong_type &rhs) &&noexcept(noexcept(m_value % rhs.m_value)) -> strong_type
	calculates the remainder of the contained values
constexpr auto	operator% (strong_type &&rhs) &&noexcept(noexcept(m_value % rhs.m_value)) -> strong_type
	calculates the remainder of the contained values
constexpr auto	operator~ () const &noexcept(noexcept(~m_value)) -> strong_type
	inverts the contained value
constexpr auto	operator& (const strong_type &rhs) const &noexcept(noexcept(m_value &rhs.m_value)) -> strong_type
	performs binary AND on the contained values
constexpr auto	operator& (strong_type &&rhs) const &noexcept(noexcept(m_value &rhs.m_value)) -> strong_type
	performs binary AND on the contained values
constexpr auto	operator& (const strong_type &rhs) &&noexcept(noexcept(m_value &rhs.m_value)) -> strong_type
	performs binary AND on the contained values
constexpr auto	operator& (strong_type &&rhs) &&noexcept(noexcept(m_value &rhs.m_value)) -> strong_type
	performs binary AND on the contained values
constexpr auto	operator| (const strong_type &rhs) const &noexcept(noexcept(m_value|rhs.m_value)) -> strong_type
	performs binary OR on the contained values
constexpr auto	operator| (strong_type &&rhs) const &noexcept(noexcept(m_value|rhs.m_value)) -> strong_type
	performs binary OR on the contained values
constexpr auto	operator| (const strong_type &rhs) &&noexcept(noexcept(m_value|rhs.m_value)) -> strong_type
	performs binary OR on the contained values
constexpr auto	operator| (strong_type &&rhs) &&noexcept(noexcept(m_value|rhs.m_value)) -> strong_type
	performs binary OR on the contained values
constexpr auto	operator^ (const strong_type &rhs) const &noexcept(noexcept(m_value ^ rhs.m_value)) -> strong_type
	performs binary XOR on the contained values
constexpr auto	operator^ (strong_type &&rhs) const &noexcept(noexcept(m_value ^ rhs.m_value)) -> strong_type
	performs binary XOR on the contained values
constexpr auto	operator^ (const strong_type &rhs) &&noexcept(noexcept(m_value ^ rhs.m_value)) -> strong_type
	performs binary XOR on the contained values
constexpr auto	operator^ (strong_type &&rhs) &&noexcept(noexcept(m_value ^ rhs.m_value)) -> strong_type
	performs binary XOR on the contained values
constexpr auto	operator<< (const strong_type &rhs) const &noexcept(noexcept(m_value<< rhs.m_value)) -> strong_type
	performs binary left shift on the contained values
constexpr auto	operator<< (strong_type &&rhs) const &noexcept(noexcept(m_value<< rhs.m_value)) -> strong_type
	performs binary left shift on the contained values
constexpr auto	operator<< (const strong_type &rhs) &&noexcept(noexcept(m_value<< rhs.m_value)) -> strong_type
	performs binary left shift on the contained values
constexpr auto	operator<< (strong_type &&rhs) &&noexcept(noexcept(m_value<< rhs.m_value)) -> strong_type
	performs binary left shift on the contained values
constexpr auto	operator>> (const strong_type &rhs) const &noexcept(noexcept(m_value > > rhs.m_value)) -> strong_type
	performs binary right shift on the contained values
constexpr auto	operator>> (strong_type &&rhs) const &noexcept(noexcept(m_value > > rhs.m_value)) -> strong_type
	performs binary right shift on the contained values
constexpr auto	operator>> (const strong_type &rhs) &&noexcept(noexcept(m_value > > rhs.m_value)) -> strong_type
	performs binary right shift on the contained values
constexpr auto	operator>> (strong_type &&rhs) &&noexcept(noexcept(m_value > > rhs.m_value)) -> strong_type
	performs binary right shift on the contained values
constexpr auto	begin () const noexcept(noexcept(std::ranges::begin(m_value)))
	returns an iterator to the beginning of the contained value
constexpr auto	begin () noexcept(noexcept(std::ranges::begin(m_value)))
	returns an iterator to the beginning of the contained value
constexpr auto	end () const noexcept(noexcept(std::ranges::end(m_value)))
	returns an iterator to the end of the contained value
constexpr auto	end () noexcept(noexcept(std::ranges::end(m_value)))
	returns an iterator to the end of the contained value

Friends
auto	operator<< (std::ostream &ostream, const strong_type &rhs) noexcept(noexcept(ostream<< rhs.m_value)) -> std::ostream &
	inserts formatted data
auto	operator>> (std::istream &istream, strong_type &rhs) noexcept(noexcept(istream > > rhs.m_value)) -> std::istream &
	extracts formatted data

Detailed Description

template<typename T, typename Tag>
class gw::strong_type< T, Tag >

Strong type wrapper.

The class template gw::strong_type is a simple wrapper around a value of some type T. It is intended to be used to create a new type that is distinct from T, but which has the same representation and semantics as T. This is useful to distinguish between values that are conceptually different, but which have the same underlying type. For example, a std::string can be used to represent a person's name, but it can also be used to represent a person's address. Using gw::strong_type to create a name_t and an address_t allows the compiler to catch errors where a name_t is used where an address_t is expected, and vice versa.

Examples

strong_type_example.cpp.

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The documentation for this class was generated from the following file:

• /home/runner/work/gw/gw/include/gw/strong_type.hpp