Hello Jasen!

Replying to a message of Jasen Betts to Neil Heller:

 JB> Hi Neil.

 JB> 24-Dec-02 23:18:02, Neil Heller wrote to Jasen Betts

 NH>> The number is always an integer:  "0" <= x <=
"250".

 JB> I has a little look in my C++ manual (it's not very good) and I
 JB> couldn't find "cstring" so I'm guessing you're just using C strings
 JB> (type char*)

I'm assuming that Neil is differentiating between the C-style strings
(herein "cstring") vs the C++-style "string" class.

 NH>> The way it turned out, what must be done is the multiply the
 NH>> number by 8.  That is, if the cstring was "135", what
needs to be put
 NH>> back in the cstring is "1080".

 JB> eg:
 JB>   sprintf(string,"%d",atoi(string)*8);

 JB> that's vanilla C code, there may be an OO version of the same
 JB> expression but I haven't been using c++ for long enough to figure
 JB> oout what it is.

There is - but it's way more convoluted because Neil is not currently using
C++ strings.

    string new_val = atoi(old_val) * 8;

That's the easy part.  After that, you have to claim the memory:

    mystruct->val[1] = strdup(new_val.c_str());

While this doesn't look that convoluted, the amount of stuff happening
under the covers is immense.  Further, the first line may not work on some
compilers.  Try:

    string new_val;
    new_val << (atoi(old_val) * 8);

Or on some compilers that won't work either.

    istrstream new_val_str;
    new_val_str << (atoi(old_val) * 8);
    string new_val = // I can't recall offhand how to get the string from
an istrstream.

Good luck!

Darin
C_PLUSPLUS moderator
dmcbride{at}tower.to.org

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