[jk-jeon]

Not sure what you mean by decimal points. Did you mean the number of decimal digits to be printed in total, or the number of digits after the decimal dot, or something else?

In any case, what Dragonbox and other modern floating-point formatting algorithms do is already roughly what you describe: they compute the integer consisting of digits to be printed, and then print those digits, except:

- Dragonbox and some of other algorithms have totally different requirements than `printf`. The user does not request the precision, rather the algorithm determines the number of digits to print. So `1.2` is printed as `1.2` and `1.199999999999` is printed as `1.199999999999`. You can read about the exact requirements in the Readme page of Dragonbox.

- The core of modern floating-point formatting algorithms is on how to compute the needed multiplication by a power of 10 without needing to do it by the plain bignum arithmetic (which is incredibly slow). Note that a `float` (assuming it's IEEE-754 binary32) instance can be as large as 2^100 or as small as 2^-100. It's nontrivial to deal with these numbers without incorporating bignum arithmetic, and even if you just give up avoiding it, bignum arithmetic itself is quite nontrivial in terms of the code size it requires.