在一行中连接多个字符串 C++

Question

我试图重载运算符“<<”以获得与 std::stringstream 类似的行为。我想在一行中连接多个字符串，并将它们传递给行中最后一个单词后的另一个函数。

struct Log
{
    std::string outString;

    template<typename T>
    friend Log& operator<<(Log& log, const T& t)
    {
        std::stringstream temp;
        temp << t;
        std::string str = temp.str();
        log.outString += str;
        if(str == "endl" || str == "\n")
        {
            //end of line -> pass string to custom print function
        }
        return log;
    }
};

我在这一行中遇到分段错误：

log.outString += str;

应该这样称呼

log << "blub: " << 123 << "endl";

Answer 1

您正在比较语句 if(t == "endl" || t== "\n") 中的整数，请将其替换为 if(str == "endl" || str == "\n")。

完整代码如下：

#include <iostream>
#include <string>
#include <sstream>

struct Logg
{
    std::string outString;

    template<typename T>
    friend Logg& operator<<(Logg& logg, const T& t)
    {
        std::stringstream temp;
        temp << t;
        std::string str = temp.str();
        logg.outString += str;
        if(str == "endl" || str == "\n")
        {
            //end of line -> pass string to custom print function
        }
        return logg;
    }
};

int main()
{
    struct Logg logg;
    logg << "blub: " << 123 << "endl";
    std::cout << logg.outString << std::endl;

    return 0;
}

在一行中连接多个字符串 C++

concating multiple strings in one line c++

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