Question

I have following program. Oddly, i expect zero, but the program thinks it is 48. If i debug this program, i can see the value assigned as 48, but if i print the value of “someVar”, it displays correctly as 0. But if i convert “someVar” to uint16_t, then everything works fine. Can you please explain the issue

#include "boost/cstdint.hpp"
#include <iostream>
#include "boost/lexical_cast.hpp"

using namespace boost;
int main(int argc, char ** args)
{
  uint8_t someVar = lexical_cast<uint8_t> (args[1]);
  if (someVar > 0)
    cout << "greater than zero" << endl;

  return 0;
}

Answer 1

The character zero ('0' is indeed 48, where the number zero as an integer, obviously indeed IS zero). If you make a lexical_cast<int>, it will do what you want, and convert the args[1] into an integer number from the string. Since uint8_t is a character, I suspect lexical cast does what you ask for, and give you the first character of the string.