#pragma once
#include <memory>
#include "Test.hpp"
namespace smart_pointer {
class exception : std::exception {
using base_class = std::exception;
using base_class::base_class;
};
template<typename T, typename Allocator>
class SmartPointer {
ENABLE_CLASS_TESTS;
public:
using value_type = T;
explicit SmartPointer(value_type *p = nullptr) {
if (p == nullptr) {
core = nullptr;
} else {
core = new Core;
core->m_obj = p;
core->count_ptr = 1;
}
}
// copy constructor
SmartPointer(const SmartPointer &p) {
if (core != nullptr) {
if (core->count_ptr > 1) {
core->count_ptr -= 1;
} else {
delete core->m_obj;
delete core;
core = new Core;
}
}
core = p.core;
if (core != nullptr)
core->count_ptr += 1;
}
// move constructor
SmartPointer(SmartPointer &&p) {
if (core != nullptr) {
if (core->count_ptr > 1) {
core->count_ptr -= 1;
} else {
delete core->m_obj;
delete core;
core = new Core;
}
}
core = p.core;
if (p.core != nullptr)
p.core = nullptr;
}
~SmartPointer() {
if (core == nullptr) {
delete core;
} else if (core->count_ptr > 1) {
core->count_ptr -= 1;
} else {
if (core->m_obj != nullptr)
delete core->m_obj;
delete core;
}
}
// copy assigment
SmartPointer &operator=(const SmartPointer &p) {
if (core != nullptr) {
if (core->count_ptr > 1) {
core->count_ptr -= 1;
} else {
delete this->core->m_obj;
delete this->core;
core = nullptr;
}
}
core = p.core;
if (core != nullptr)
core->count_ptr += 1;
return *this;
}
// move assigment
SmartPointer &operator=(SmartPointer &&p) {
if (core != nullptr) {
if (core->count_ptr > 1) {
core->count_ptr -= 1;
} else {
delete core->m_obj;
delete core;
}
}
core = p.core;
if (core != nullptr) {
p.core = nullptr;
}
return *this;
}
SmartPointer &operator=(value_type *p) {
if (core != nullptr) {
if (core->count_ptr > 1) {
core->count_ptr -= 1;
} else {
delete core->m_obj;
delete core;
core = new Core;
}
} else {
core = new Core;
}
if (p != nullptr) {
core->m_obj = p;
} else {
delete core;
core = nullptr;
}
if (core != nullptr)
core->count_ptr = 1;
return *this;
}
value_type &operator*() {
if (get() == nullptr)
throw exception();
else
return *core->m_obj;
}
const value_type &operator*() const {
if (get() == nullptr)
throw exception();
else
return *core->m_obj;
}
value_type *operator->() const {
return core ? core->m_obj : nullptr;
}
value_type *get() const {
return core ? core->m_obj : nullptr;
}
operator bool() const {
return core != nullptr;
}
template<typename U, typename AnotherAllocator>
bool operator==(const SmartPointer<U, AnotherAllocator> &p) const {
return (p.get() == nullptr && get() == nullptr) ||
(p.get() != nullptr && get() != nullptr &&
*p.get() == *get() &&
static_cast<void *>(p.get()) == static_cast<void *>(get()));
}
template<typename U, typename AnotherAllocator>
bool operator!=(const SmartPointer<U, AnotherAllocator> &p) const {
return !((p.get() == nullptr && get() == nullptr) ||
(p.get() != nullptr && get() != nullptr &&
*p.get() == *get() &&
static_cast<void *>(p.get()) ==
static_cast<void *>(get())));
}
[[nodiscard]] std::size_t count_owners() const {
if (core != nullptr)
return core->count_ptr;
return 0;
}
private:
class Core {
public:
value_type *m_obj;
std::size_t count_ptr;
};
Core *core = nullptr;
};
} // namespace smart_pointer