Cpp/C++ - Is this an alternative to tolower? : I was solving a very easy problem to convert a character in a string to lowercase, I obviously used tolower(). However, I saw someone use this and it was an accepted solution. 

**Is this an alternative to tolower() function in cpp? If so, why?**

Reference to the problem: https://atcoder.jp/contests/abc126/tasks/abc126_a

    #include <iostream>
    using namespace std;
     
    int main(int argc, char const *argv[])
    {
        // We want to convert "ABC" to "aBC"
        string S = "ABC";
        S[0] += 0x20;
        // Returns "aBC"
        cout << S << endl;
        return 0;
    }