1.
int a = 10;
char *intStr = itoa(a);
string str = string(intStr);
2.
int a = 10;
stringstream ss;
ss << a;
string str = ss.str();
3. C++11 (推荐,如果支持的话)
#include <string>
std::string s = std::to_string(42);
4. C++ 98即可 (不支持C++11就用这个或者2,233 )
#include <sstream>
#define SSTR( x ) static_cast< std::ostringstream & >( \
( std::ostringstream() << std::dec << x ) ).str()
5. Boost
#include <boost/lexical_cast.hpp>
int num = 4;
std::string str = boost::lexical_cast<std::string>(num);