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libcow/include/cow/typed.hpp

122 lines
4.0 KiB

#pragma once
#include <cow.hpp>
#include <utility>
template<typename T>
struct TypedCow : public _cow_util::Span<T> {
struct Fake;
template<typename... Args>
inline TypedCow(size_t sz, Args&&... args) : real(Cow(sz * sizeof(T))) { init_copy( T(std::forward<Args>(args)...) ); }
inline TypedCow(size_t sz, const T& copy) : real(Cow(sz * sizeof(T))) { init_copy(copy); }
inline TypedCow(size_t sz) : TypedCow(sz, T()){}
inline virtual ~TypedCow() { uninit(); }
inline virtual Fake clone() const { return Fake(*this); }
inline virtual cow_t* raw() const { return real.raw(); }
inline size_t size() const { return real.size() / sizeof(T); }
protected:
//inline explicit TypedCow(const TypedCow<T>& unsafeCopy) : real(Cow(unsafeCopy.real)){}
inline virtual void* area() override { return reinterpret_cast<void*>( real.ptr() ); }
inline virtual const void* area() const override { return reinterpret_cast<const void*>( real.ptr() ); }
inline void init_copy(const T& copy_from) {
T* ptr = this->ptr();
for(size_t i=0;i<size();i++)
new ((void*)(ptr+i)) T(copy_from);
}
// UNSAFE: Explicitly calls destructors of each element in this instance.
inline void uninit() {
T* ptr = this->ptr();
if(!ptr) return;
for(size_t i=0;i<size();i++)
(ptr+i)->~T();
}
private:
Cow real;
};
template<typename T>
struct TypedCow<T>::Fake : public TypedCow<T> {
//XXX: How THE FUCK do we initialise base's `real` here?????
Fake() = delete;
inline Fake(const Fake& copy) : fake(cow_clone(copy.fake)){}
inline Fake(Fake&& move) : fake(move.fake) { *const_cast<cow_t**>(&move.fake) = nullptr; }
inline Fake(const TypedCow<T>& clone) : fake(cow_clone(clone.raw())){}
inline cow_t* raw() const override { return fake; }
inline Fake clone() const override { return Fake(*this); }
inline ~Fake(){}
inline size_t size() const override { return fake ? cow_size(fake) : 0; }
protected:
inline void* area() override { return fake ? cow_ptr(fake) : nullptr; }
inline const void* area() const override { return fake ? cow_ptr_of(const void, fake) : nullptr; }
private:
cow_t* const fake;
};
#if 0
struct Fake;
friend class Fake;
TypedCow() = delete;
inline TypedCow(TypedCow<T>&& move) : Cow(std::move(move.super)) { /* Moves the shared_ptr. No need to move the elements. */ }
// protected: copy
inline TypedCow(size_t sz) : Cow(sz * sizeof(T)) { init_copy(T()); }
inline TypedCow(size_t sz, const T& copy_from) : TypedCow(sz) { init_copy(copy_from); }
//template<typename... Args>
//inline TypedCow(size_t sz, Args&&... args) : TypedCow(sz) { init_copy( T(std::forward<Args>(args)...) ); }
virtual inline ~TypedCow() { uninit(); }
inline Cow::Fake clone() const override { return Cow::clone(); }
inline Fake clone() const { return Fake(Cow::clone()); }
inline size_t size() const override { return Cow::size() / sizeof(T); }
protected:
inline void* area() override { return Cow::area(); }
inline const void* area() const override { return Cow::area(); }
//// Should only be used for creating Fakes. Copies the refcounted pointer.
//inline TypedCow(const TypedCow<T>& copy) : Cow(copy.super) {}
// UNSAFE: Placement-new's copys of `copy_from` into `0..size()` of this instance.
inline void init_copy(const T& copy_from) {
T* ptr = _cow_util::Span<T>::ptr();
for(size_t i=0;i<size();i++)
new ((void*)(ptr+i)) T(copy_from);
}
// UNSAFE: Explicitly calls destructors of each element in this instance.
inline void uninit() {
T* ptr = _cow_util::Span<T>::ptr();
for(size_t i=0;i<size();i++)
(ptr+i)->~T();
}
};
template<typename T>
struct TypedCow<T>::Fake : private Cow::Fake, public _cow_util::Span<T> {
Fake() = delete;
explicit inline Fake(Cow::Fake&& untyped) : Cow::Fake(untyped){}
inline Fake(const Fake& copy) : Fake(copy.Cow::Fake::clone()){}
inline Fake(Fake&& move) : Cow::Fake(std::move(move)) {}
inline ~Fake(){}
inline size_t size() const override { return Cow::Fake::size(); }
protected:
inline const void* area() const override { return Cow::Fake::area(); }
inline void* area() override { return Cow::Fake::area(); }
};
#endif