How to concatenate a std::string and an int?

Question

I thought this would be really simple but it\'s presenting some difficulties. If I have

std::string name = \"John\";
int age = 21;

How do I

Answer 1

• std::ostringstream

#include 

std::ostringstream s;
s << "John " << age;
std::string query(s.str());

• std::to_string (C++11)

std::string query("John " + std::to_string(age));

• boost::lexical_cast

#include 

std::string query("John " + boost::lexical_cast(age));