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authorSteven Le Rouzic <steven.lerouzic@gmail.com>2025-02-17 00:21:48 +0100
committerSteven Le Rouzic <steven.lerouzic@gmail.com>2025-02-17 22:29:50 +0100
commita141c401f78467bc15f62882fca5d55a007cacbb (patch)
tree908ac71a8640f78f45d22c6808c5fa6e373000fa /asl/option.hpp
parentcb77cbe9ce4cddad6a460aa190ff70f0c13e4703 (diff)
Reorganize everything
Diffstat (limited to 'asl/option.hpp')
-rw-r--r--asl/option.hpp509
1 files changed, 0 insertions, 509 deletions
diff --git a/asl/option.hpp b/asl/option.hpp
deleted file mode 100644
index d12d4ce..0000000
--- a/asl/option.hpp
+++ /dev/null
@@ -1,509 +0,0 @@
-#pragma once
-
-#include "asl/assert.hpp"
-#include "asl/meta.hpp"
-#include "asl/maybe_uninit.hpp"
-#include "asl/functional.hpp"
-#include "asl/annotations.hpp"
-#include "asl/hash.hpp"
-
-namespace asl
-{
-
-struct nullopt_t {};
-static constexpr nullopt_t nullopt{};
-
-// @Todo(option) Reference
-// @Todo(option) Function
-// @Todo(option) Arrays
-
-template<is_object T> class option;
-
-namespace option_internal
-{
-
-template<typename T, typename U>
-concept not_constructible_from_option =
- !constructible_from<T, option<U>&> &&
- !constructible_from<T, const option<U>&> &&
- !constructible_from<T, option<U>&&> &&
- !constructible_from<T, const option<U>&&>;
-
-template<typename T, typename U>
-concept not_assignable_from_option =
- !assignable_from<T&, option<U>&> &&
- !assignable_from<T&, const option<U>&> &&
- !assignable_from<T&, option<U>&&> &&
- !assignable_from<T&, const option<U>&&>;
-
-template<typename T, typename U>
-concept not_constructible_assignable_from_option =
- not_constructible_from_option<T, U> &&
- not_assignable_from_option<T, U>;
-
-} // namespace option_internal
-
-template<typename T>
-concept is_option = requires
-{
- typename T::type;
- requires same_as<un_cvref_t<T>, option<typename T::type>>;
-};
-
-template<is_object T>
-class option
-{
- static constexpr bool kHasNiche = has_niche<T>;
-
- using HasValueMarker = select_t<kHasNiche, empty, bool>;
-
- maybe_uninit<T> m_payload{};
- ASL_NO_UNIQUE_ADDRESS HasValueMarker m_has_value{};
-
- template<is_object U>
- friend class option;
-
- template<typename... Args>
- constexpr void construct(Args&&... args)
- {
- ASL_ASSERT(!has_value());
-
- if constexpr (!kHasNiche)
- {
- m_payload.construct_unsafe(ASL_FWD(args)...);
- m_has_value = true;
- }
- else
- {
- if constexpr (move_assignable<T>)
- {
- m_payload.assign_unsafe(ASL_MOVE(T{ASL_FWD(args)...}));
- }
- else
- {
- m_payload.destroy_unsafe();
- m_payload.construct_unsafe(ASL_FWD(args)...);
- }
- }
- }
-
- template<typename U>
- constexpr void assign(U&& arg)
- {
- ASL_ASSERT(has_value());
- m_payload.assign_unsafe(ASL_FWD(arg));
- }
-
-public:
- using type = T;
-
- constexpr option() : option{nullopt} {}
-
- // NOLINTNEXTLINE(*-explicit-conversions)
- constexpr option(nullopt_t) requires (!kHasNiche) {}
-
- // NOLINTNEXTLINE(*-explicit-conversions)
- constexpr option(nullopt_t) requires kHasNiche : m_payload{in_place, niche_t{}} {}
-
- template<typename U = T>
- constexpr explicit (!convertible_from<T, U&&>)
- option(U&& value)
- requires (
- kHasNiche &&
- constructible_from<T, U&&> &&
- !same_as<un_cvref_t<U>, option>
- )
- : m_payload{in_place, ASL_FWD(value)}
- {}
-
- template<typename U = T>
- constexpr explicit (!convertible_from<T, U&&>)
- option(U&& value)
- requires (
- !kHasNiche &&
- constructible_from<T, U&&> &&
- !is_option<U>
- )
- : m_payload{in_place, ASL_FWD(value)}
- , m_has_value{true}
- {}
-
- constexpr option(const option& other) requires trivially_copy_constructible<T> = default;
- constexpr option(const option& other) requires (!copy_constructible<T>) = delete;
-
- constexpr option(const option& other)
- requires copy_constructible<T> && (!trivially_copy_constructible<T>)
- : option{nullopt}
- {
- if (other.has_value())
- {
- construct(other.m_payload.as_init_unsafe());
- }
- }
-
- constexpr option(option&& other) requires trivially_move_constructible<T> = default;
- constexpr option(option&& other) requires (!move_constructible<T>) = delete;
-
- constexpr option(option&& other)
- requires move_constructible<T> && (!trivially_move_constructible<T>)
- : option{nullopt}
- {
- if (other.has_value())
- {
- construct(ASL_MOVE(other.m_payload.as_init_unsafe()));
- }
- }
-
- template<typename U>
- constexpr explicit (!convertible_from<T, const U&>)
- option(const option<U>& other)
- requires (
- constructible_from<T, const U&> &&
- option_internal::not_constructible_from_option<T, U>
- )
- : option{nullopt}
- {
- if (other.has_value())
- {
- construct(other.m_payload.as_init_unsafe());
- }
- }
-
- template<typename U>
- constexpr explicit (!convertible_from<T, U&&>)
- option(option<U>&& other)
- requires (
- constructible_from<T, U&&> &&
- option_internal::not_constructible_from_option<T, U>
- )
- : option{nullopt}
- {
- if (other.has_value())
- {
- construct(ASL_MOVE(other.m_payload.as_init_unsafe()));
- }
- }
-
- constexpr option& operator=(nullopt_t) &
- {
- reset();
- return *this;
- }
-
- template<typename U = T>
- constexpr option& operator=(U&& value) &
- requires (
- assignable_from<T&, U&&> &&
- constructible_from<T, U&&> &&
- !is_option<U>
- )
- {
- if (has_value())
- {
- assign(ASL_FWD(value));
- }
- else
- {
- construct(ASL_FWD(value));
- }
-
- return *this;
- }
-
- constexpr option& operator=(const option& other) &
- requires (!copy_assignable<T>) = delete;
-
- constexpr option& operator=(const option& other) &
- requires trivially_copy_assignable<T> = default;
-
- constexpr option& operator=(const option& other) &
- requires copy_assignable<T> && (!trivially_copy_constructible<T>)
- {
- if (&other == this) { return *this; }
-
- if (other.has_value())
- {
- if (has_value())
- {
- assign(other.m_payload.as_init_unsafe());
- }
- else
- {
- construct(other.m_payload.as_init_unsafe());
- }
- }
- else if (has_value())
- {
- reset();
- }
-
- return *this;
- }
-
- constexpr option& operator=(option&& other) &
- requires (!move_assignable<T>) = delete;
-
- constexpr option& operator=(option&& other) &
- requires trivially_move_assignable<T> = default;
-
- constexpr option& operator=(option&& other) &
- requires move_assignable<T> && (!trivially_move_constructible<T>)
- {
- if (&other == this) { return *this; }
-
- if (other.has_value())
- {
- if (has_value())
- {
- assign(ASL_MOVE(other.m_payload.as_init_unsafe()));
- }
- else
- {
- construct(ASL_MOVE(other.m_payload.as_init_unsafe()));
- }
- }
- else if (has_value())
- {
- reset();
- }
-
- return *this;
- }
-
- template<typename U = T>
- constexpr option& operator=(const option<U>& other) &
- requires (
- constructible_from<T, const U&> &&
- assignable_from<T&, const U&> &&
- option_internal::not_constructible_assignable_from_option<T, U>
- )
- {
- if (other.has_value())
- {
- if (has_value())
- {
- assign(other.m_payload.as_init_unsafe());
- }
- else
- {
- construct(other.m_payload.as_init_unsafe());
- }
- }
- else if (has_value())
- {
- reset();
- }
-
- return *this;
- }
-
- template<typename U = T>
- constexpr option& operator=(option<U>&& other) &
- requires (
- constructible_from<T, U&&> &&
- assignable_from<T&, U&&> &&
- option_internal::not_constructible_assignable_from_option<T, U>
- )
- {
- if (other.has_value())
- {
- if (has_value())
- {
- assign(ASL_MOVE(other.m_payload.as_init_unsafe()));
- }
- else
- {
- construct(ASL_MOVE(other.m_payload.as_init_unsafe()));
- }
- }
- else if (has_value())
- {
- reset();
- }
-
- return *this;
- }
-
- constexpr ~option() requires trivially_destructible<T> = default;
- constexpr ~option() requires (!trivially_destructible<T>)
- {
- reset();
- }
-
- constexpr void reset()
- {
- if (!has_value()) { return; }
-
- if constexpr (kHasNiche)
- {
- if constexpr (move_assignable<T>)
- {
- m_payload.assign_unsafe(ASL_MOVE(T{niche_t{}}));
- }
- else
- {
- m_payload.destroy_unsafe();
- m_payload.construct_unsafe(niche_t{});
- }
- }
- else
- {
- m_has_value = false;
- m_payload.destroy_unsafe();
- }
- }
-
- constexpr bool has_value() const
- {
- if constexpr (kHasNiche)
- {
- return m_payload.as_init_unsafe() != niche_t{};
- }
- else
- {
- return m_has_value;
- }
- }
-
- // @Todo(C++23) Deducing this
- constexpr T&& value() &&
- {
- ASL_ASSERT_RELEASE(has_value());
- return ASL_MOVE(m_payload).as_init_unsafe();
- }
-
- constexpr T& value() &
- {
- ASL_ASSERT_RELEASE(has_value());
- return m_payload.as_init_unsafe();
- }
-
- constexpr const T& value() const&
- {
- ASL_ASSERT_RELEASE(has_value());
- return m_payload.as_init_unsafe();
- }
-
- template<typename U>
- constexpr T value_or(U&& other_value) const&
- requires copy_constructible<T> && convertible_from<T, U&&>
- {
- return has_value() ? value() : static_cast<T>(ASL_FWD(other_value));
- }
-
- template<typename U>
- constexpr T value_or(U&& other_value) &&
- requires move_constructible<T> && convertible_from<T, U&&>
- {
- return has_value() ? ASL_MOVE(value()) : static_cast<T>(ASL_FWD(other_value));
- }
-
- template<typename... Args>
- constexpr T& emplace(Args&&... args) &
- requires constructible_from<T, Args&&...>
- {
- if (has_value()) { reset(); }
- construct(ASL_FWD(args)...);
- return value();
- }
-
- template<typename F>
- constexpr auto and_then(F&& f) &
- requires is_option<result_of_t<F(T&)>>
- {
- if (has_value())
- {
- return invoke(ASL_FWD(f), value());
- }
- return un_cvref_t<result_of_t<F(T&)>>{};
- }
-
- template<typename F>
- constexpr auto and_then(F&& f) const&
- requires is_option<result_of_t<F(const T&)>>
- {
- if (has_value())
- {
- return invoke(ASL_FWD(f), value());
- }
- return un_cvref_t<result_of_t<F(const T&)>>{};
- }
-
- template<typename F>
- constexpr auto and_then(F&& f) &&
- requires is_option<result_of_t<F(T)>>
- {
- if (has_value())
- {
- return invoke(ASL_FWD(f), ASL_MOVE(value()));
- }
- return un_cvref_t<result_of_t<F(T)>>{};
- }
-
- template<typename F>
- constexpr auto transform(F&& f) &
- {
- using U = un_cvref_t<result_of_t<F(T&)>>;
- if (has_value())
- {
- return option<U>{ invoke(ASL_FWD(f), value()) };
- }
- return option<U>{};
- }
-
- template<typename F>
- constexpr auto transform(F&& f) const&
- {
- using U = un_cvref_t<result_of_t<F(const T&)>>;
- if (has_value())
- {
- return option<U>{ invoke(ASL_FWD(f), value()) };
- }
- return option<U>{};
- }
-
- template<typename F>
- constexpr auto transform(F&& f) &&
- {
- using U = un_cvref_t<result_of_t<F(T)>>;
- if (has_value())
- {
- return option<U>{ invoke(ASL_FWD(f), ASL_MOVE(value())) };
- }
- return option<U>{};
- }
-
- template<typename F>
- constexpr option or_else(F&& f) const&
- requires same_as<un_cvref_t<result_of_t<F()>>, option>
- {
- return has_value() ? *this : invoke(ASL_FWD(f));
- }
-
- template<typename F>
- constexpr option or_else(F&& f) &&
- requires same_as<un_cvref_t<result_of_t<F()>>, option>
- {
- return has_value() ? ASL_MOVE(*this) : invoke(ASL_FWD(f));
- }
-
- template<typename H>
- requires (!uniquely_represented<option>) && hashable<T>
- friend H AslHashValue(H h, const option& opt)
- {
- if (!opt.has_value())
- {
- return H::combine(ASL_MOVE(h), 0);
- }
- return H::combine(ASL_MOVE(h), 1, opt.value());
- }
-};
-
-template<typename T>
-requires has_niche<T> && uniquely_represented<T>
-struct is_uniquely_represented<option<T>> : true_type {};
-
-template<typename T>
-option(T) -> option<T>;
-
-} // namespace asl