-
-
Notifications
You must be signed in to change notification settings - Fork 21.6k
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Core: Implement
Nullable<T> template
- Loading branch information
Showing
11 changed files
with
392 additions
and
18 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,209 @@ | ||
| /**************************************************************************/ | ||
| /* nullable.h */ | ||
| /**************************************************************************/ | ||
| /* This file is part of: */ | ||
| /* GODOT ENGINE */ | ||
| /* https://godotengine.org */ | ||
| /**************************************************************************/ | ||
| /* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */ | ||
| /* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */ | ||
| /* */ | ||
| /* Permission is hereby granted, free of charge, to any person obtaining */ | ||
| /* a copy of this software and associated documentation files (the */ | ||
| /* "Software"), to deal in the Software without restriction, including */ | ||
| /* without limitation the rights to use, copy, modify, merge, publish, */ | ||
| /* distribute, sublicense, and/or sell copies of the Software, and to */ | ||
| /* permit persons to whom the Software is furnished to do so, subject to */ | ||
| /* the following conditions: */ | ||
| /* */ | ||
| /* The above copyright notice and this permission notice shall be */ | ||
| /* included in all copies or substantial portions of the Software. */ | ||
| /* */ | ||
| /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */ | ||
| /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */ | ||
| /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */ | ||
| /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */ | ||
| /* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */ | ||
| /* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */ | ||
| /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ | ||
| /**************************************************************************/ | ||
|
|
||
| #ifndef NULLABLE_H | ||
| #define NULLABLE_H | ||
|
|
||
| #include "core/typedefs.h" | ||
|
|
||
| #include <type_traits> | ||
|
|
||
| /** | ||
| * A template wrapper meant to allow value-types to also be assigned null. The | ||
| * internal value should be validated as non-null before being handled as a | ||
| * proper value. Includes null-coalescing operators `<<` and `<<=` that're meant | ||
| * to mirror C#'s `??` and `??=` respectively. | ||
| * | ||
| * Despite containing a pointer, this isn't meant to be handled as a pointer type | ||
| * in the traditional sense. The syntax is setup in such a way to enforce the idea | ||
| * that this is the type it's wrapping, if that type could also be assigned and | ||
| * compared against `nullptr`. | ||
| */ | ||
|
|
||
| template <typename T> | ||
| class [[nodiscard]] Nullable { | ||
| T *value; | ||
| template <typename T_Other> | ||
| static constexpr bool is_implicitly_convertible_v = std::is_constructible_v<T, T_Other> && std::is_convertible_v<T_Other, T>; | ||
| template <typename T_Other> | ||
| static constexpr bool is_explicitly_convertible_v = std::is_constructible_v<T, T_Other> && !std::is_convertible_v<T_Other, T>; | ||
|
|
||
| public: | ||
| _ALWAYS_INLINE_ Nullable() : | ||
| value(nullptr) {} | ||
|
|
||
| _ALWAYS_INLINE_ Nullable(std::nullptr_t) : | ||
| value(nullptr) {} | ||
|
|
||
| _ALWAYS_INLINE_ Nullable(const T &p_value) : | ||
| value(memnew(T(p_value))) {} | ||
|
|
||
| template <typename T_Other, std::enable_if_t<is_implicitly_convertible_v<T_Other>, int> = 0> | ||
| _ALWAYS_INLINE_ Nullable(const T_Other &p_value) : | ||
| value(memnew(T(p_value))) {} | ||
|
|
||
| template <typename T_Other, std::enable_if_t<is_explicitly_convertible_v<T_Other>, int> = 0> | ||
| _ALWAYS_INLINE_ explicit Nullable(const T_Other &p_value) : | ||
| value(memnew(T(p_value))) {} | ||
|
|
||
| _ALWAYS_INLINE_ Nullable(const Nullable &p_other) : | ||
| value(p_other.value) {} | ||
|
|
||
| template <typename T_Other, std::enable_if_t<is_implicitly_convertible_v<T_Other>, int> = 0> | ||
| _ALWAYS_INLINE_ Nullable(const Nullable<T_Other> &p_other) { | ||
| if (p_other.has_value()) { | ||
| operator=(*p_other); | ||
| } | ||
| } | ||
|
|
||
| template <typename T_Other, std::enable_if_t<is_explicitly_convertible_v<T_Other>, int> = 0> | ||
| _ALWAYS_INLINE_ explicit Nullable(const Nullable<T_Other> &p_other) { | ||
| if (p_other.has_value()) { | ||
| operator=((T_Other)*p_other); | ||
| } | ||
| } | ||
|
|
||
| _ALWAYS_INLINE_ ~Nullable() { | ||
| if (value != nullptr) { | ||
| memdelete(value); | ||
| } | ||
| value = nullptr; | ||
| } | ||
|
|
||
| _ALWAYS_INLINE_ T &operator*() const { | ||
| DEV_ASSERT(value != nullptr); | ||
| return *value; | ||
| } | ||
|
|
||
| _ALWAYS_INLINE_ void operator=(std::nullptr_t) { | ||
| if (value != nullptr) { | ||
| memdelete(value); | ||
| } | ||
| value = nullptr; | ||
| } | ||
|
|
||
| _ALWAYS_INLINE_ void operator=(const T &p_value) { | ||
| if (value == nullptr) { | ||
| value = memnew(T); | ||
| } | ||
| *value = p_value; | ||
| } | ||
|
|
||
| template <typename T_Other, std::enable_if_t<std::is_convertible_v<T, T_Other>, int> = 0> | ||
| _ALWAYS_INLINE_ void operator=(const T_Other &p_value) { | ||
| if (value == nullptr) { | ||
| value = memnew(T); | ||
| } | ||
| *value = (T)p_value; | ||
| } | ||
|
|
||
| _ALWAYS_INLINE_ void operator=(const Nullable &p_other) { | ||
| if (unlikely(this == &p_other)) { | ||
| return; | ||
| } else if (p_other.value == nullptr) { | ||
| operator=(nullptr); | ||
| } else { | ||
| operator=(*p_other); | ||
| } | ||
| } | ||
|
|
||
| template <typename T_Other, std::enable_if_t<std::is_convertible_v<T, T_Other>, int> = 0> | ||
| _ALWAYS_INLINE_ void operator=(const Nullable<T_Other> &p_other) { | ||
| if (unlikely(this == &p_other)) { | ||
| return; | ||
| } else if (p_other.value == nullptr) { | ||
| operator=(nullptr); | ||
| } else { | ||
| operator=(*p_other); | ||
| } | ||
| } | ||
|
|
||
| _ALWAYS_INLINE_ bool is_null() const { return value == nullptr; } | ||
| _ALWAYS_INLINE_ bool has_value() const { return value != nullptr; } | ||
|
|
||
| _ALWAYS_INLINE_ bool operator==(std::nullptr_t) const { return is_null(); } | ||
| _ALWAYS_INLINE_ bool operator!=(std::nullptr_t) const { return has_value(); } | ||
|
|
||
| _ALWAYS_INLINE_ bool operator==(const T &p_value) const { return is_null() ? false : *value == p_value; } | ||
| _ALWAYS_INLINE_ bool operator!=(const T &p_value) const { return is_null() ? true : *value != p_value; } | ||
|
|
||
| template <typename T_Other, std::enable_if_t<std::is_convertible_v<T, T_Other>, int> = 0> | ||
| _ALWAYS_INLINE_ bool operator==(const T_Other &p_value) const { return is_null() ? false : *value == p_value; } | ||
| template <typename T_Other, std::enable_if_t<std::is_convertible_v<T, T_Other>, int> = 0> | ||
| _ALWAYS_INLINE_ bool operator!=(const T_Other &p_value) const { return is_null() ? true : *value != p_value; } | ||
|
|
||
| _ALWAYS_INLINE_ bool operator==(const Nullable &p_other) const { return p_other.is_null() ? p_other.is_null() : (p_other.is_null() ? false : *value == *p_other.value); } | ||
| _ALWAYS_INLINE_ bool operator!=(const Nullable &p_other) const { return p_other.is_null() ? p_other.has_value() : (p_other.is_null() ? true : *value != *p_other.value); } | ||
|
|
||
| template <typename T_Other, std::enable_if_t<std::is_convertible_v<T, T_Other>, int> = 0> | ||
| _ALWAYS_INLINE_ bool operator==(const Nullable &p_other) const { return p_other.is_null() ? p_other.is_null() : (p_other.is_null() ? false : *value == *p_other.value); } | ||
| template <typename T_Other, std::enable_if_t<std::is_convertible_v<T, T_Other>, int> = 0> | ||
| _ALWAYS_INLINE_ bool operator!=(const Nullable &p_other) const { return p_other.is_null() ? p_other.has_value() : (p_other.is_null() ? true : *value != *p_other.value); } | ||
|
|
||
| // Null coalescing operators. | ||
|
|
||
| _ALWAYS_INLINE_ T operator<<(const T &p_value) const { return has_value() ? *value : p_value; } | ||
|
|
||
| template <typename T_Other, std::enable_if_t<std::is_convertible_v<T, T_Other>, int> = 0> | ||
| _ALWAYS_INLINE_ T operator<<(const T_Other &p_value) const { return has_value() ? *value : T(p_value); } | ||
|
|
||
| _ALWAYS_INLINE_ void operator<<=(const T &p_value) { | ||
| if (is_null()) { | ||
| value = memnew(T(p_value)); | ||
| } | ||
| } | ||
|
|
||
| template <typename T_Other, std::enable_if_t<std::is_convertible_v<T, T_Other>, int> = 0> | ||
| _ALWAYS_INLINE_ void operator<<=(const T_Other &p_value) { | ||
| if (is_null()) { | ||
| value = memnew(T(p_value)); | ||
| } | ||
| } | ||
|
|
||
| _ALWAYS_INLINE_ Nullable operator<<(const Nullable &p_other) const { return has_value() ? this : p_other; } | ||
|
|
||
| template <typename T_Other, std::enable_if_t<std::is_convertible_v<T, T_Other>, int> = 0> | ||
| _ALWAYS_INLINE_ Nullable operator<<(const Nullable &p_other) const { return has_value() ? this : T(p_other); } | ||
|
|
||
| _ALWAYS_INLINE_ void operator<<=(const Nullable &p_other) { | ||
| if (is_null()) { | ||
| operator=(p_other); | ||
| } | ||
| } | ||
|
|
||
| template <typename T_Other, std::enable_if_t<std::is_convertible_v<T, T_Other>, int> = 0> | ||
| _ALWAYS_INLINE_ void operator<<=(const Nullable &p_other) { | ||
| if (is_null()) { | ||
| operator=(p_other); | ||
| } | ||
| } | ||
| }; | ||
|
|
||
| #endif // NULLABLE_H |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.