C++ Efficient Container-Vector-Implement Low-Level-Reference Counting Class

C++ Efficient Container-Vector-Implement Low-Level-Reference Counting Class

Note: I am original, if you find similarities, you will be responsible for the consequences

Note that C++ 17
will be used to implement the unified namespacecustom

design

1. In order to achieve implicit sharing, reference counting will be used to achieve
2. Count member variables using atomic operations

File name: Ref_count.hpp
namespace: custom
class name: Ref_count
included header files: cstddefandatomic

Member type	Types of	effect
count_type	std::size_t	计数的类型

Types of	Member variables	effect
std::atomic<count_type>	_atomic	计数

函数	作用
inline bool ref() noexcept	表示有引用的对象, 返回true就是引用成功
inline bool deref() noexcept	表示有对象取消引用, 返回true就是还有对象引用
inline count_type count() const noexcept	返回引用的对象个数

achieve

// Ref_count.hpp
#ifndef REF_COUNT_HPP
#define REF_COUNT_HPP

#include <cstddef>
#include <atomic>

namespace custom
{
    
    

class Ref_count
{
    
    
public:
	using count_type = std::size_t;
	
	std::atomic<count_type> _atomic;

public:
	
	inline bool ref() noexcept
    {
    
    
        count_type count = _atomic.load();
        
        if (count == 0 || count == invalid_size || count+1 == invalid_size)
        {
    
    
            return false;
        }
        
        ++_atomic;
        
        return true;
    }
    
    inline bool deref() noexcept
    {
    
    
        count_type count = _atomic.load();
        
        if (count == 0)
        {
    
    
            return false;
        }
        
        if (count == invalid_size)
        {
    
    
            return true;
        }

        return (--_atomic) != 0;
    }
    
    inline count_type count() const noexcept
    {
    
    
        return _atomic.load();
    }
};

} // custom

#endif // REF_COUNT_HPP

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