C++中string和int互相转换

int转string
int n = 123;
std::stringstream ss;
std::string str;
ss<<n;
ss>>str;
string转int
1.

std::string str = "123";
int n = atoi(str.c_str());
2.

std::string str = "123";
std::stringstream ss;
int n;
ss<<str;
ss>>n;