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#ifndef ref_ptr_hh_INCLUDED
#define ref_ptr_hh_INCLUDED
namespace Kakoune
{
struct RefCountable
{
RefCountable() = default;
RefCountable(const RefCountable&) {}
RefCountable(RefCountable&&) {}
virtual ~RefCountable() = default;
RefCountable& operator=(const RefCountable&) { return *this; }
RefCountable& operator=(RefCountable&&) { return *this; }
int refcount = 0;
};
struct RefCountablePolicy
{
static void inc_ref(RefCountable* r, void*) noexcept { ++r->refcount; }
static void dec_ref(RefCountable* r, void*) noexcept { if (--r->refcount == 0) delete r; }
static void ptr_moved(RefCountable*, void*, void*) noexcept {}
};
template<typename T, typename Policy = RefCountablePolicy>
struct RefPtr
{
RefPtr() = default;
explicit RefPtr(T* ptr) : m_ptr(ptr) { acquire(); }
~RefPtr() noexcept { release(); }
RefPtr(const RefPtr& other) : m_ptr(other.m_ptr) { acquire(); }
RefPtr(RefPtr&& other)
noexcept(noexcept(moved(nullptr)))
: m_ptr(other.m_ptr) { other.m_ptr = nullptr; moved(&other); }
RefPtr& operator=(const RefPtr& other)
{
if (other.m_ptr != m_ptr)
{
release();
m_ptr = other.m_ptr;
acquire();
}
return *this;
}
RefPtr& operator=(RefPtr&& other)
{
release();
m_ptr = other.m_ptr;
other.m_ptr = nullptr;
moved(&other);
return *this;
}
RefPtr& operator=(T* ptr)
{
if (ptr != m_ptr)
{
release();
m_ptr = ptr;
acquire();
}
return *this;
}
[[gnu::always_inline]]
T* operator->() const { return m_ptr; }
[[gnu::always_inline]]
T& operator*() const { return *m_ptr; }
[[gnu::always_inline]]
T* get() const { return m_ptr; }
[[gnu::always_inline]]
explicit operator bool() const { return m_ptr; }
void reset(T* ptr = nullptr)
{
if (ptr == m_ptr)
return;
release();
m_ptr = ptr;
acquire();
}
friend bool operator==(const RefPtr& lhs, const RefPtr& rhs) = default;
friend bool operator==(const RefPtr& lhs, const T* rhs) { return lhs.m_ptr == rhs; }
private:
T* m_ptr = nullptr;
[[gnu::always_inline]]
void acquire()
{
if (m_ptr)
Policy::inc_ref(m_ptr, this);
}
[[gnu::always_inline]]
void release() noexcept
{
if (m_ptr)
Policy::dec_ref(m_ptr, this);
}
[[gnu::always_inline]]
void moved(void* from)
noexcept(noexcept(Policy::ptr_moved(nullptr, nullptr, nullptr)))
{
if (m_ptr)
Policy::ptr_moved(m_ptr, from, this);
}
};
}
#endif // ref_ptr_hh_INCLUDED
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