C++ 簡單的字符串轉換

1. #include <iostream>
2. #include <string>
3. #include <sstream>
4. #include <complex>
6. using namespace std;
8. template<typename T>
9. T fromString(const string &s)
10. {
11. istringstream is(s);
12. T t;
13. is >> t;
15. return t;
16. }
18. template<typename T>
19. string toString(const T &t)
20. {
21. ostringstream s;
22. s << t;
24. return s.str();
25. }
27. int main(int argc, char *argv[])
28. {
29. int i = 12345;
30. cout << "i == \"" << toString(i) << "\"" << endl;
31. float x = 567.89;
32. cout << "x == \"" << toString(x) << "\"" << endl;
33. complex<float> c(1.0, 2.0);
34. cout << "c == \"" << toString(c) << "\"" << endl << endl;
36. i = fromString<int>(string("1234"));
37. cout << "i == " << i << endl;
39. x = fromString<float>(string("567.89"));
40. cout << "x == " << x << endl;
42. c = fromString< complex<float> >(string("(1.0, 2.0)"));
43. cout << "c == " << c << endl;
45. return 0;
46. }

運行結果為：

i == "12345"
x == "567.89"
c == "(1,2)"


i == 1234
x == 567.89
c == (1,2)