c++ integer->std::string conversion. Simple functi

问题:

Problem: I have an integer; this integer needs to be converted to a stl::string type.

In the past, I've used stringstream to do a conversion, and that's just kind of cumbersome. I know the C way is to do a sprintf, but I'd much rather do a C++ method that is typesafe(er).

Is there a better way to do this?

Here is the stringstream approach I have used in the past:

std::string intToString(int i)
{
    std::stringstream ss;
    std::string s;
    ss << i;
    s = ss.str();

    return s;
}

Of course, this could be rewritten as so:

template<class T>
std::string t_to_string(T i)
{
    std::stringstream ss;
    std::string s;
    ss << i;
    s = ss.str();

    return s;
}

However, I have the notion that this is a fairly 'heavy-weight' implementation.

Zan noted that the invocation is pretty nice, however:

std::string s = t_to_string(my_integer);

At any rate, a nicer way would be... nice.

Related:

Alternative to itoa() for converting integer to string C++?

回答1:

Now in c++11 we have

#include <string>
string s = std::to_string(123);

Link to reference: http://en.cppreference.com/w/cpp/string/basic_string/to_string

回答2:

Like mentioned earlier, I'd recommend boost lexical_cast. Not only does it have a fairly nice syntax:

#include <boost/lexical_cast.hpp>
std::string s = boost::lexical_cast<std::string>(i);

it also provides some safety:

try{
  std::string s = boost::lexical_cast<std::string>(i);
}catch(boost::bad_lexical_cast &){
 ...
}

回答3:

Not really, in the standard. Some implementations have a nonstandard itoa() function, and you could look up Boost's lexical_cast, but if you stick to the standard it's pretty much a choice between stringstream and sprintf() (snprintf() if you've got it).