C++ vector 中 double 与 int8_t 转化

逃离我推掉我的手 2023-06-21 11:27 1阅读 0赞

### 1. vector<double> 转化为 vector<int8\_t> ###

void EncodeDouble(const std::vector<double>& data, std::vector<int8_t>& result)
    {
        const double *dataPtr = data.data();
        uint32_t dataSize = data.size() * sizeof(double);
        std::size_t    current = 0;
    
        while (current + sizeof(int8_t) <= dataSize)
        {
            int8_t val;
            memcpy(&val, (uint8_t*)dataPtr + current, sizeof(val));
            current += sizeof(val);
            result.push_back(val);
        }
    }

### 2. vector<int8\_t> 转化为 vector<double> ###

void DecodeToDouble(const std::vector<int8_t>& data, std::vector<double>& result)
    {
        const int8_t *dataPtr = data.data();
        uint32_t dataSize = data.size() * sizeof(int8_t);
        std::size_t    current = 0;
    
        while (current + sizeof(double) <= dataSize)
        {
            double val;
            memcpy(&val, (uint8_t*)dataPtr + current, sizeof(val));
            current += sizeof(val);
            result.push_back(val);
        }
    }

### 3.测试 ###

#include <iostream>
    #include <vector>
    
    int main()
    {
        std::vector<double> data = { 1.2, 4.5, 10.0, 12.3 };
    
        std::vector<int8_t> encodeData;
        EncodeDouble(data, encodeData);
    
        std::vector<double> decodeData;
        DecodeToDouble(encodeData, decodeData);
        for (auto iter = decodeData.begin(); iter != decodeData.end(); iter++)
        {
            std::cout << *iter << " ";
        }
        std::cout << std::endl;
    
        getchar();
        return 0;
    }

### 4.运行结果 ###

![20191212162559625.png][]

[20191212162559625.png]: https://img-blog.csdnimg.cn/20191212162559625.png