Uppercase

#include <cctype>
#include <iostream>
#include <sstream>
#include <string>
using namespace std;
string uppercase(string& s) {
  stringstream out;
  for (auto& e : s)
    out << static_cast<char>(toupper(e));
  return out.str();
}
int main() {
  string s;
  cout << "文字列? ";
  getline(cin, s);
  cout << uppercase(s) << endl;
}