#pragma once
#include <memory>
#include "Test.hpp"
namespace smart_pointer {
// `exception` class definition
class exception : std::exception {
using base_class = std::exception;
using base_class::base_class;
};
// `SmartPointer` class declaration
template<
typename T,
typename Allocator
>
class SmartPointer {
// don't remove this macro
ENABLE_CLASS_TESTS;
public:
using value_type = T;
explicit SmartPointer(value_type *ptr = nullptr) {
if (ptr != nullptr) {
core = new Core(ptr);
} else {
core = nullptr;
}
}
// copy constructor
SmartPointer(const SmartPointer &other) {
core = other.core;
if (core != nullptr) {
core->count_++;
}
}
// move constructor
SmartPointer(SmartPointer &&other) {
core = other.core;
other.core = nullptr;
}
// copy assigment
SmartPointer &operator=(const SmartPointer &other) {
if (this != &other) {
this->~SmartPointer();
core = other.core;
if (core != nullptr) {
core->count_++;
}
}
return *this;
}
// move assigment
SmartPointer &operator=(SmartPointer &&other) {
if (this != &other) {
this->~SmartPointer();
core = other.core;
other.core = nullptr;
}
return *this;
}
//
SmartPointer &operator=(value_type *ptr) {
this->~SmartPointer();
if (ptr != nullptr) {
core = new Core(ptr);
} else {
core = nullptr;
}
return *this;
}
~SmartPointer() {
if (core != nullptr) {
core->count_--;
if (core->count_ == 0) {
delete core;
}
}
}
// return reference to the object of class/type T
// if SmartPointer contains nullptr throw `SmartPointer::exception`
value_type &operator*() {
if (core != nullptr) {
return *(core->ptr_);
} else {
throw smart_pointer::exception();
}
}
const value_type &operator*() const {
if (core != nullptr) {
return *(core->ptr_);
} else {
throw smart_pointer::exception();
}
}
// return pointer to the object of class/type T
value_type *operator->() const {
if (core != nullptr) {
return core->ptr_;
} else {
return nullptr;
}
}
value_type *get() const {
if (core != nullptr) {
return core->ptr_;
} else {
return nullptr;
}
}
// if pointer == nullptr => return false
operator bool() const {
if (core == nullptr) {
return false;
}
return true;
}
// if pointers points to the same address or both null => true
template<typename U, typename AnotherAllocator>
friend
class SmartPointer;
template<typename U, typename AnotherAllocator>
bool operator==(const SmartPointer<U, AnotherAllocator> &other) const {
if (static_cast<void *>(core) == static_cast<void *>(other.core)) {
return true;
}
return false;
}
// if pointers points to the same address or both null => false
template<typename U, typename AnotherAllocator>
bool operator!=(const SmartPointer<U, AnotherAllocator> &other) const {
if (static_cast<void *>(core) == static_cast<void *>(other.core)) {
return false;
}
return true;
}
// if smart pointer contains non-nullptr => return count owners
// if smart pointer contains nullptr => return 0
std::size_t count_owners() const {
if (core != nullptr) {
return core->count_;
} else {
return 0;
}
}
private:
class Core {
public:
explicit Core(T *ptr = 0) {
ptr_ = ptr;
if (ptr != 0) {
count_ = 1;
} else {
count_ = 0;
}
}
~Core() {
delete ptr_;
}
size_t count_;
T *ptr_;
};
Core *core;
};
} // namespace smart_pointer