mirror of
https://github.com/bolero-MURAKAMI/Sprout.git
synced 2024-12-25 21:35:41 +00:00
353 lines
11 KiB
C++
353 lines
11 KiB
C++
#ifndef SPROUT_OPTIONAL_OPTIONAL_HPP
|
|
#define SPROUT_OPTIONAL_OPTIONAL_HPP
|
|
|
|
#include <type_traits>
|
|
#include <initializer_list>
|
|
#include <sprout/config.hpp>
|
|
#include <sprout/utility/value_holder/value_holder.hpp>
|
|
#include <sprout/utility/value_holder/get.hpp>
|
|
#include <sprout/utility/swap.hpp>
|
|
#include <sprout/utility/forward.hpp>
|
|
#include <sprout/utility/move.hpp>
|
|
#include <sprout/type_traits/is_convert_constructible.hpp>
|
|
#include <sprout/none.hpp>
|
|
#include <sprout/optional/nullopt.hpp>
|
|
#include <sprout/optional/in_place.hpp>
|
|
#include <sprout/optional/exceptions.hpp>
|
|
#include <sprout/assert.hpp>
|
|
|
|
namespace sprout {
|
|
//
|
|
// optional
|
|
//
|
|
template<typename T>
|
|
class optional {
|
|
public:
|
|
typedef T type;
|
|
private:
|
|
typedef sprout::value_holder<type> holder_type;
|
|
public:
|
|
typedef typename holder_type::value_type value_type;
|
|
typedef typename holder_type::lvalue_reference lvalue_reference;
|
|
typedef typename holder_type::rvalue_reference rvalue_reference;
|
|
typedef typename holder_type::reference reference;
|
|
typedef typename holder_type::const_lvalue_reference const_lvalue_reference;
|
|
typedef typename holder_type::const_rvalue_reference const_rvalue_reference;
|
|
typedef typename holder_type::const_reference const_reference;
|
|
typedef typename holder_type::pointer pointer;
|
|
typedef typename holder_type::const_pointer const_pointer;
|
|
typedef typename holder_type::lvalue_reference_type lvalue_reference_type;
|
|
typedef typename holder_type::rvalue_reference_type rvalue_reference_type;
|
|
typedef typename holder_type::reference_type reference_type;
|
|
typedef typename holder_type::reference_const_type reference_const_type;
|
|
typedef typename holder_type::pointer_type pointer_type;
|
|
typedef typename holder_type::pointer_const_type pointer_const_type;
|
|
public:
|
|
template<typename... Args>
|
|
struct is_constructible_args
|
|
: public std::is_constructible<T, Args&&...>
|
|
{};
|
|
public:
|
|
static SPROUT_CONSTEXPR reference_type get(optional& t) SPROUT_NOEXCEPT {
|
|
return sprout::get(t.val);
|
|
}
|
|
static SPROUT_CONSTEXPR rvalue_reference_type get(optional&& t) SPROUT_NOEXCEPT {
|
|
return static_cast<rvalue_reference_type>(get(t));
|
|
}
|
|
static SPROUT_CONSTEXPR reference_const_type get(optional const& t) SPROUT_NOEXCEPT {
|
|
return sprout::get(t.val);
|
|
}
|
|
static SPROUT_CONSTEXPR pointer_type get_pointer(optional& t) SPROUT_NOEXCEPT {
|
|
return sprout::get_pointer(t.val);
|
|
}
|
|
static SPROUT_CONSTEXPR pointer_type get_pointer(optional&& t) SPROUT_NOEXCEPT {
|
|
return get_pointer(t);
|
|
}
|
|
static SPROUT_CONSTEXPR pointer_const_type get_pointer(optional const& t) SPROUT_NOEXCEPT {
|
|
return sprout::get_pointer(t.val);
|
|
}
|
|
static SPROUT_CONSTEXPR reference_type get_value_or(optional& t, reference_type v) SPROUT_NOEXCEPT {
|
|
return t.is_initialized() ? sprout::get(t.val)
|
|
: v
|
|
;
|
|
}
|
|
static SPROUT_CONSTEXPR rvalue_reference_type get_value_or(optional&& t, rvalue_reference_type v) SPROUT_NOEXCEPT {
|
|
return static_cast<rvalue_reference_type>(get_value_or(t, v));
|
|
}
|
|
static SPROUT_CONSTEXPR reference_const_type get_value_or(optional const& t, reference_const_type v) SPROUT_NOEXCEPT {
|
|
return t.is_initialized() ? sprout::get(t.val)
|
|
: v
|
|
;
|
|
}
|
|
private:
|
|
bool init;
|
|
holder_type val;
|
|
private:
|
|
void destroy() SPROUT_NOEXCEPT {
|
|
init = false;
|
|
}
|
|
public:
|
|
// 20.6.4.1, constructors
|
|
SPROUT_CONSTEXPR optional() SPROUT_NOEXCEPT
|
|
: init(false)
|
|
{}
|
|
SPROUT_CONSTEXPR optional(sprout::nullopt_t) SPROUT_NOEXCEPT
|
|
: init(false)
|
|
{}
|
|
SPROUT_CONSTEXPR optional(optional const& v)
|
|
: init(v.init)
|
|
, val(v.is_initialized() ? holder_type(*v) : holder_type())
|
|
{}
|
|
#if defined(__GNUC__) && (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ == 8 && __GNUC_PATCHLEVEL__ <= 1))
|
|
SPROUT_CONSTEXPR optional(optional&&) = default;
|
|
#else
|
|
SPROUT_CONSTEXPR optional(optional&& v)
|
|
SPROUT_NOEXCEPT_EXPR(std::is_nothrow_move_constructible<T>::value)
|
|
: init(v.init)
|
|
, val(v.is_initialized() ? holder_type(sprout::move(get(v))) : holder_type())
|
|
{}
|
|
#endif
|
|
SPROUT_CONSTEXPR optional(T const& v)
|
|
: init(true)
|
|
, val(v)
|
|
{}
|
|
SPROUT_CONSTEXPR optional(T&& v)
|
|
: init(true)
|
|
, val(sprout::move(v))
|
|
{}
|
|
template<
|
|
typename... Args,
|
|
typename = typename std::enable_if<is_constructible_args<Args...>::value>::type
|
|
>
|
|
explicit SPROUT_CONSTEXPR optional(sprout::in_place_t, Args&&... args)
|
|
: init(true)
|
|
, val(sprout::in_place, sprout::forward<Args>(args)...)
|
|
{}
|
|
template<
|
|
typename U, typename... Args,
|
|
typename = typename std::enable_if<is_constructible_args<std::initializer_list<U>&, Args...>::value>::type
|
|
>
|
|
explicit SPROUT_CONSTEXPR optional(sprout::in_place_t, std::initializer_list<U> il, Args&&... args)
|
|
: init(true)
|
|
, val(sprout::in_place, il, sprout::forward<Args>(args)...)
|
|
{}
|
|
SPROUT_CONSTEXPR optional(bool cond, T const& v)
|
|
: init(cond)
|
|
, val(cond ? holder_type(v) : holder_type())
|
|
{}
|
|
SPROUT_CONSTEXPR optional(bool cond, T&& v)
|
|
: init(cond)
|
|
, val(cond ? holder_type(sprout::move(v)) : holder_type())
|
|
{}
|
|
template<typename U>
|
|
explicit SPROUT_CONSTEXPR optional(optional<U> const& v)
|
|
: init(v.is_initialized())
|
|
, val(v.is_initialized() ? holder_type(*v) : holder_type())
|
|
{}
|
|
template<typename U>
|
|
explicit SPROUT_CONSTEXPR optional(optional<U>&& v)
|
|
: init(v.is_initialized())
|
|
, val(v.is_initialized() ? holder_type(sprout::move(optional<U>::get(v))) : holder_type())
|
|
{}
|
|
// 20.6.4.3, assignment
|
|
optional& operator=(sprout::nullopt_t v) SPROUT_NOEXCEPT {
|
|
assign(v);
|
|
return *this;
|
|
}
|
|
optional& operator=(optional const& v) {
|
|
assign(v);
|
|
return *this;
|
|
}
|
|
optional& operator=(optional&& v)
|
|
SPROUT_NOEXCEPT_EXPR(std::is_move_constructible<T>::value && std::is_move_assignable<T>::value)
|
|
{
|
|
assign(sprout::forward<optional>(v));
|
|
return *this;
|
|
}
|
|
template<
|
|
typename U,
|
|
// typename = typename std::enable_if<std::is_constructible<T, U>::value && std::is_assignable<U, T>::value>::type
|
|
typename = typename std::enable_if<std::is_constructible<T, U&&>::value>::type
|
|
>
|
|
optional& operator=(U&& v) {
|
|
assign(sprout::forward<U>(v));
|
|
return *this;
|
|
}
|
|
template<typename U>
|
|
optional& operator=(optional<U> const& v) {
|
|
assign(v);
|
|
return *this;
|
|
}
|
|
template<typename U>
|
|
optional& operator=(optional<U>&& v) {
|
|
assign(sprout::forward<optional<U> >(v));
|
|
return *this;
|
|
}
|
|
|
|
template<
|
|
typename... Args,
|
|
typename = typename std::enable_if<is_constructible_args<Args...>::value>::type
|
|
>
|
|
void emplace(Args&&... args) {
|
|
optional temp(sprout::in_place, sprout::forward<Args>(args)...);
|
|
temp.swap(*this);
|
|
}
|
|
template<
|
|
typename U, typename... Args,
|
|
typename = typename std::enable_if<is_constructible_args<std::initializer_list<U>&, Args...>::value>::type
|
|
>
|
|
void emplace(std::initializer_list<U> il, Args&&... args) {
|
|
optional temp(sprout::in_place, il, sprout::forward<Args>(args)...);
|
|
temp.swap(*this);
|
|
}
|
|
|
|
void assign(sprout::nullopt_t) SPROUT_NOEXCEPT {
|
|
destroy();
|
|
}
|
|
void assign(optional const& v) {
|
|
optional temp(v);
|
|
temp.swap(*this);
|
|
}
|
|
void assign(optional&& v)
|
|
SPROUT_NOEXCEPT_EXPR(std::is_move_constructible<T>::value && std::is_move_assignable<T>::value)
|
|
{
|
|
optional temp(sprout::forward<optional>(v));
|
|
temp.swap(*this);
|
|
}
|
|
template<
|
|
typename U,
|
|
// typename = typename std::enable_if<std::is_constructible<T, U>::value && std::is_assignable<U, T>::value>::type
|
|
typename = typename std::enable_if<std::is_constructible<T, U&&>::value>::type
|
|
>
|
|
void assign(U&& v) {
|
|
optional temp(sprout::forward<U>(v));
|
|
temp.swap(*this);
|
|
}
|
|
template<typename U>
|
|
void assign(optional<U> const& v) {
|
|
optional temp(v);
|
|
temp.swap(*this);
|
|
}
|
|
template<typename U>
|
|
void assign(optional<U>&& v) {
|
|
optional temp(sprout::forward<optional<U> >(v));
|
|
temp.swap(*this);
|
|
}
|
|
|
|
void reset() SPROUT_NOEXCEPT {
|
|
destroy();
|
|
}
|
|
void reset(sprout::nullopt_t v) SPROUT_NOEXCEPT {
|
|
assign(v);
|
|
}
|
|
template<
|
|
typename U,
|
|
// typename = typename std::enable_if<std::is_constructible<T, U>::value && std::is_assignable<U, T>::value>::type
|
|
typename = typename std::enable_if<std::is_constructible<T, U&&>::value>::type
|
|
>
|
|
void reset(U&& v) {
|
|
assign(sprout::forward<U>(v));
|
|
}
|
|
// 20.6.4.4, swap
|
|
void swap(optional& other)
|
|
SPROUT_NOEXCEPT_EXPR(SPROUT_NOEXCEPT_EXPR(sprout::swap(val, other.val)))
|
|
{
|
|
sprout::swap(init, other.init);
|
|
sprout::swap(val, other.val);
|
|
}
|
|
// 20.6.4.5, observers
|
|
SPROUT_CONSTEXPR pointer_const_type operator->() const {
|
|
return SPROUT_ASSERT(is_initialized()),
|
|
val.get_pointer()
|
|
;
|
|
}
|
|
pointer_type operator->() {
|
|
return SPROUT_ASSERT(is_initialized()),
|
|
val.get_pointer()
|
|
;
|
|
}
|
|
SPROUT_CONSTEXPR pointer_const_type get_pointer() const {
|
|
return is_initialized() ? val.get_pointer()
|
|
: 0
|
|
;
|
|
}
|
|
pointer_type get_pointer() {
|
|
return is_initialized() ? val.get_pointer()
|
|
: 0
|
|
;
|
|
}
|
|
SPROUT_CONSTEXPR pointer_const_type get_ptr() const {
|
|
return get_pointer();
|
|
}
|
|
pointer_type get_ptr() {
|
|
return get_pointer();
|
|
}
|
|
|
|
SPROUT_CONSTEXPR reference_const_type operator*() const {
|
|
return (SPROUT_ASSERT(is_initialized()), true) ? val.get()
|
|
: val.get()
|
|
;
|
|
}
|
|
reference_type operator*() {
|
|
return (SPROUT_ASSERT(is_initialized()), true) ? val.get()
|
|
: val.get()
|
|
;
|
|
}
|
|
SPROUT_CONSTEXPR reference_const_type value() const {
|
|
return get();
|
|
}
|
|
reference_type value() {
|
|
return get();
|
|
}
|
|
SPROUT_CONSTEXPR reference_const_type get() const {
|
|
return is_initialized() ? val.get()
|
|
: (throw sprout::bad_optional_access("optional<>: bad optional access"), val.get())
|
|
;
|
|
}
|
|
reference_type get() {
|
|
return is_initialized() ? val.get()
|
|
: (throw sprout::bad_optional_access("optional<>: bad optional access"), val.get())
|
|
;
|
|
}
|
|
|
|
SPROUT_CONSTEXPR reference_const_type value_or(reference_const_type& v) const {
|
|
return get_value_or(v);
|
|
}
|
|
reference_type value_or(reference_type& v) {
|
|
return get_value_or(v);
|
|
}
|
|
SPROUT_CONSTEXPR reference_const_type get_value_or(reference_const_type& v) const {
|
|
return is_initialized() ? val.get()
|
|
: v
|
|
;
|
|
}
|
|
reference_type get_value_or(reference_type& v) {
|
|
return is_initialized() ? val.get()
|
|
: v
|
|
;
|
|
}
|
|
|
|
SPROUT_EXPLICIT_CONVERSION SPROUT_CONSTEXPR operator bool() const SPROUT_NOEXCEPT {
|
|
return is_initialized();
|
|
}
|
|
SPROUT_CONSTEXPR bool operator!() const SPROUT_NOEXCEPT {
|
|
return !is_initialized();
|
|
}
|
|
SPROUT_CONSTEXPR bool is_initialized() const SPROUT_NOEXCEPT {
|
|
return init;
|
|
}
|
|
};
|
|
|
|
//
|
|
// swap
|
|
//
|
|
template<typename T>
|
|
inline void
|
|
swap(sprout::optional<T>& lhs, sprout::optional<T>& rhs)
|
|
SPROUT_NOEXCEPT_EXPR(SPROUT_NOEXCEPT_EXPR(lhs.swap(rhs)))
|
|
{
|
|
lhs.swap(rhs);
|
|
}
|
|
} // namespace sprout
|
|
|
|
#endif // #ifndef SPROUT_OPTIONAL_OPTIONAL_HPP
|