Question

I have following code:

int n=2;
ostringstream convert;   // stream used for the conversion
convert << n; 
string query= convert.str();

How can I free ostringstream?

Answer 1

With lifetime management:

std::string query;
int n = 2;

{
    std::ostringstream oss;
    oss << n;
    query = oss.str();
}

Shorter, but a bit tougher to read:

int n = 2;
std::string query
          = static_cast<std::ostringstream &>(std::ostringstream() << n).str();

Possibly better, depending on your situation:

auto query = std::to_string(2);