Question

I’m working on a little console game with ncurses. In the main menu I want the user to be able to set the control keys. Now as far as I understood, in ncurses you can access e.a. the a-key by the int value of the char ‘a’. Using the key ingame with ‘a’ works flawlessly, however I’m stuck with the menu:

For each key binding I have stored an int-value that is defaulted to e.a. ‘a’. When the game starts, I read the ‘a’ binding correctly from the int-value and can use it ingame. However, it is not displayed correctly. I want it to be like this: “Left: a”. I do it like this:

std::string key = "Left: " + static_cast<char>(_value);

_value being the int-value I stored and initialized as ‘a’. I also tried it without the cast, btw.

Now what’s being displayed is strange. Instead of “a” it says “~T^C”. For the letters “s” and “d” it doesn’t display anything at all. “w” becomes some very strange encoding question marks.

I suppose it’s got something to do with the encoding of the characters in int-values or something. So what can I do to get it displayed the right way?

Thanks a lot!

Answer 1

You’re adding together the adress of string literal and ASCII value of _value. String key is then constructed from whatever happens to be at that garbage adress.

Remember that string literals are of type array of N const char and that arrays decay to pointer to their first element when passed to functions and operators etc., which yields you const char*. The built in + operator for pointers doesn’t do string concatenation. You need to construct a std::string from at least one of operands for overloaded operator to kick in:

std::string key = std::string("Left: ") + static_cast<char>(_value);