RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-07-26 01:57:45 +00:00
Code Issues Activity Actions

AK: Make Optional<T> explicitly constructible from Optional<U>

Browse source 
As long as T is constructible from U. This allows us to avoid patterns
like `abc.has_value() ? Optional<U>(abc.value()) : Optional<U>()`.
This commit is contained in:
Idan Horowitz 2022-01-23 13:03:29 +02:00
parent fb06d494f0
commit a3a4d0aea2
1 changed files with 21 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

25
AK/Optional.h
View file

@ -24,6 +24,9 @@ namespace AK {
template<typename T> template<typename T>
class [[nodiscard]] Optional { class [[nodiscard]] Optional {
template<typename U>
friend class Optional;
public: public:
using ValueType = T; using ValueType = T;
@ -50,17 +53,31 @@ public:
#endif #endif
: m_has_value(other.m_has_value) : m_has_value(other.m_has_value)
{ {
if (other.has_value()) { if (other.has_value())
new (&m_storage) T(other.value()); new (&m_storage) T(other.value());
}
} }
ALWAYS_INLINE Optional(Optional&& other) ALWAYS_INLINE Optional(Optional&& other)
: m_has_value(other.m_has_value) : m_has_value(other.m_has_value)
{ {
if (other.has_value()) { if (other.has_value())
new (&m_storage) T(other.release_value());
}
template<typename U>
requires(IsConstructible<T, U const&> && !IsSpecializationOf<T, Optional> && !IsSpecializationOf<U, Optional>) ALWAYS_INLINE explicit Optional(Optional<U> const& other)
: m_has_value(other.m_has_value)
{
if (other.has_value())
new (&m_storage) T(other.value());
}
template<typename U>
requires(IsConstructible<T, U&&> && !IsSpecializationOf<T, Optional> && !IsSpecializationOf<U, Optional>) ALWAYS_INLINE explicit Optional(Optional<U>&& other)
: m_has_value(other.m_has_value)
{
if (other.has_value())
new (&m_storage) T(other.release_value()); new (&m_storage) T(other.release_value());
}
} }
template<typename U = T> template<typename U = T>