The Decimal data type I am referring to is GNU MPFR(https://en.wikipedia.org/wiki/GNU_MPFR), or libmpdec (http://www.bytereef.org/mpdecimal/doc/libmpdec/index.html).
I have been searching for information about decimal for days and learned that you can use fixed-point (int + scaling factor) to represent a non-int real number, but I have looked into the above two libraries, which doesn't look like fixed-point. Instead, they refer to the implementation as (correctly-rounded arbitrary precision decimal floating point arithmetic).
The information online is very limited (or there are something obvious I have missed).
I would like to know more.