Passing a (char) to a (int) argument - Is it safe?

[lgb3]

Hello everyone,

I have a function in my program which receives (int)s from 0 to 9 , so it has a (int) arg, but I would like it to be able to recognize the '.' character. So what I'm doing is, just casting to (int) before passing it on to the function and inside it, casting it again to char and comparing against '.' to see if it's true. So that's how my code's like:

myfunction( (int)'.' );
 
void myfunction( int value){
  char aux = (char)value;
 
  if(aux == '.')
  cout << "TRUE";
  else
  cout << "Number : " << value;
 
 
}

myfunction( (int)'.' );

void myfunction( int value){
  char aux = (char)value;

  if(aux == '.')
  cout << "TRUE";
  else
  cout << "Number : " << value;


}

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Well, it works, it correctly recons that i'm passing '.' and do the actions I expect it to do. It also recognizes the digits.

I'm just wondering wether it is safe or not to do that, because it doesn't seem very elegant. Is it possible that in another architecture,compiler,operation system,whatever, it won't work out right?

Thanks in advance,

Luiz.

[wysota]

Yes, this is safe. As far as I remember you shouldn't even need to do the cast.

[FelixB]

what do you want to achieve? maybe there's a better solution...

[lgb3]

Yes, there was a much better solution for my case. I just wanted to know if it could be ambiguous somehow.
Thank you very much mates.

Luiz.

[SixDegrees]

Whether it's safe or not depends on what you are trying to do. One potential problem, if you're trying to pick apart something like floating point numbers, is that decimal points aren't always used as the character for digit grouping. Commas are also seen, in which case the thousands separator is switched to a decimal point. (Of course, it isn't a "decimal point" anymore, but...)

Many toolkits provide an abstraction for this character to avoid ambiguity. I don't know if Qt does this, but I wouldn't be surprised. If so, you should use that pseudo-character for comparisons, as it will change depending on the user's localization.