C++如何实现一个简单的CSV文件解析器？（代码示例）

#include <iostream>
#include <fstream>
#include <vector>
#include <string>
#include <sstream>
#include <cctype>
<p>std::vector<std::string> parse_csv_line(const std::string& line) {
std::vector<std::string> fields;
std::string field;
bool in_quotes = false;</p><pre class="brush:php;toolbar:false;">for (size_t i = 0; i < line.length(); ++i) {
    char c = line[i];
    if (c == '"') {
        in_quotes = !in_quotes;
    } else if (c == ',' && !in_quotes) {
        // 字段结束
        fields.push_back(field);
        field.clear();
    } else if (c == '\r' || c == '\n') {
        // 忽略行内换行（实际CSV中少见，但容错）
        continue;
    } else {
        // 普通字符：若在引号内且下一个是"，则只加一个"
        if (c == '"' && i + 1 < line.length() && line[i + 1] == '"') {
            field += '"';
            ++i; // 跳过下一个"
        } else {
            field += c;
        }
    }
}
fields.push_back(field); // 最后一个字段
return fields;

std::string line;
while (std::getline(file, line)) {
    auto fields = parse_csv_line(line);
    // 去空格（可选）
    for (auto& f : fields) f = trim(f);

    // 打印结果（调试用）
    std::cout << "行: [";
    for (size_t i = 0; i < fields.size(); ++i) {
        std::cout << "\"" << fields[i] << "\"";
        if (i < fields.size() - 1) std::cout << ", ";
    }
    std::cout << "]\n";
}
return 0;

Name,Age,City
"Smith, John",28,"New York"
"Alice ""The Great""",31,"San Francisco"
Bob,25,Chicago

行: ["Name", "Age", "City"]
行: ["Smith, John", "28", "New York"]
行: ["Alice \"The Great\"", "31", "San Francisco"]
行: ["Bob", "25", "Chicago"]