[C++] String Composing Tip

[wtd]

For composing long strings the temptation is to use the std::string class and its + operator. However, this results in a temporary std::string object being created each time the operator is used. Sometimes compilers can optimize this away, but it shouldn't be counted on.

Instead use the std::stringstream class.

code:

#include <sstream> #include <iostream> int main() {    std::stringstream ss;    ss << "hello";    ss << " ";    ss << "world" << std::endl;    std::cout << ss.str();    return 0; }

The same way you should use operator overloading to handle output, you can overload it to handle interactions with std::stringstream.

code:

#include <sstream> class my_class {    private:       int a, b;    public:       my_class(int, int);       friend std::stringstream& operator<<(std:stringstream&, const my_class&); }; int main() {    std::stringstream ss;    my_class c(4, 3);    ss << c << std::endl;    return 0; } my_class:my_class(int init_a = 0, int init_b = 0) : a(init_a), b(init_b) { } std::stringstream& operator<<(std:stringstream& s, const my_class& m) {    return s << m.a << " " << m.b; }