C++ extraction operator : how can one know the number of digits read?

Question

I read an integer number :

is >> myInteger;

Now I want to know how many digits were read (I'm talking of the possible leading zeros). How can I do that?

Answer 1

You can:

• get the value as a string, then parse it separately, however you wish (check length, count zeros, etc).

• use is.tellg for this; Keep in mind that tellg will give you buffer positions, not not what was at those positions (it could be space characters or zeros)

• read the buffer character by character using is.get, then process values according to your needs.