decltype() demo

#include <iostream>#include <vector>#include <string>#include <cctype>using namespace std;int main(){    vector<string> svec;    string word;    while (cin >> word)        svec.push_back(word);    for (auto &elem : svec)        for (auto &c : elem)            c = toupper(c);    for (decltype(svec.size()) ix = 0; ix != svec.size(); ++ix)        cout << svec[ix] << endl;    return 0;}