message: Simple case shuffling without relying on local and libraries
diff: *
  **************************************************************************/
  -#include <cctype>
  #include <iostream>
  #include <sstream>
  @@ -613,22 +612,17 @@ struct BenchmarkQueryInsensitiveString : BenchmarkWithStringsTable {
  return ss.str();
  }
  - std::string shuffle_case(std::string input)
  + std::string shuffle_case(std::string str)
  {
  - for (size_t i = 0; i < input.size(); ++i) {
  - bool upper = (rand() % 2) == 0;
  - int c = input[i];
  - if (upper) {
  - c = std::toupper(c);
  + for (size_t i = 0; i < str.size(); ++i) {
  + char c = str[i];
  + if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z')) {
  + bool change_case = (rand() % 2) == 0;
  + c ^= change_case ? 0x20 : 0;
  }
  - else {
  - c = std::tolower(c);
  + str[i] = c;
  }
  - if (c > 0) {
  - input[i] = c;
  - }
  - }
  - return input;
  + return str;
  }
  size_t rand() {
  