C++是否存在与Python fstring、字符串格式化功能等效的实现？

C++ 等效Python字符串格式化方案及棋盘函数改造 #

对应Python的string formatting和f-string功能，C++有成熟的等效实现，同时可以直接改造你现有的棋盘函数为返回字符串的可复用版本：

通用兼容方案（支持所有C++版本） #

使用<sstream>头文件的std::ostringstream完成字符串拼接，不需要依赖高版本标准库：

#include <string>
#include <sstream>

std::string get_board() {
    char board_pos[3][3] = {{'1', '2', '3'}, {'4', '5', '6'}, {'7', '8', '9'}};
    std::ostringstream oss;
    
    oss << "     |     |     " << "\n";
    oss << "  " << board_pos[0][0] << "  |  " << board_pos[0][1] << "  |  " << board_pos[0][2] << "  " << "\n";
    oss << "     |     |     " << "\n";
    oss << "-----------------" << "\n";
    oss << "     |     |     " << "\n";
    oss << "  " << board_pos[1][0] << "  |  " << board_pos[1][1] << "  |  " << board_pos[1][2] << "  " << "\n";
    oss << "     |     |     " << "\n";
    oss << "-----------------" << "\n";
    oss << "     |     |     " << "\n";
    oss << "  " << board_pos[2][0] << "  |  " << board_pos[2][1] << "  |  " << board_pos[2][2] << "  " << "\n";
    oss << "     |     |     " << "\n";
    
    return oss.str();
}

上层调用时直接获取返回的std::string对象即可，可直接打印或做后续处理：

// 调用示例
std::string board_str = get_board();
std::cout << board_str;

C++20 高版本最优方案 #

C++20标准库新增了std::format，语法和Python格式化字符串几乎一致，代码更简洁：

#include <string>
#include <format>

std::string get_board() {
    char board_pos[3][3] = {{'1', '2', '3'}, {'4', '5', '6'}, {'7', '8', '9'}};
    return std::format(R"(
     |     |     
  {}  |  {}  |  {}  
     |     |     
-----------------
     |     |     
  {}  |  {}  |  {}  
     |     |     
-----------------
     |     |     
  {}  |  {}  |  {}  
     |     |     
)", 
    board_pos[0][0], board_pos[0][1], board_pos[0][2],
    board_pos[1][0], board_pos[1][1], board_pos[1][2],
    board_pos[2][0], board_pos[2][1], board_pos[2][2]
    );
}

这里用到了C++11及以上支持的原生字符串字面量R"()"，可以保留字符串内的换行和空格，不需要额外转义。

内容的提问来源于stack exchange，提问作者SentBySunlight