Why does D language do not support BigDecimal type?

[Boqsc]

On Tuesday, 12 March 2019 at 08:48:33 UTC, Cym13 wrote:
> On Monday, 11 March 2019 at 15:23:34 UTC, BoQsc wrote:
>> There is Money datatype that can be provided by using a third 
>> party package: https://code.dlang.org/packages/money
>>
>> But that's only for money, what about math?
>> Why such fundamental as BigDecimal is still not included into 
>> the D language itself?
>> There is BigInt.
>>
>> If it is unavoidable to use Floating point, how can I quickly 
>> and simply understand the rules of using float to make the 
>> least error, or should I just find a third party package for 
>> that as well?
>>
>>
>> There is an article on that, but it is not that straight 
>> forward:
>> https://dlang.org/articles/d-floating-point.html
>>
>> Basically any thing that I find on Google, that include 
>> explaining floating point are badly written and hard to 
>> understand for the outsider lacking ability to understand 
>> advanced concepts.
>
> How much precision is enough in your use case? There's always a 
> limit to how precise you need to be and how precise you can be, 
> be it only because our memory is finite.
>
> I've never had a use case for BigDecimal myself, so forgive my 
> ignorance, but wouldn't you get the exact same result by using 
> BigInt?
>
> For example, if you need 20 decimals of precisions then any 
> value times 10^20 will be a BigInt on which you can work, it's 
> just a matter of displaying it correctly when outputing the 
> result but it doesn't change the operations you have to perform.
>
> Is there anything that can't be done with BigInt really?

Please attach quick working examples for every sentence you write 
or it's just a waste of time. People want to see the results and 
direct actions first before anything else, it's more efficient 
communication. We are in the subforum of Dlang learn, after all.

Do not write "For Example".

I'm interested in writing a simple game prototype and I imagine 
that I would like to include some item parts in decimal. (100.00) 
To keep everything simple I would like to make my code as clean 
and simple as possible. Floating points seems to require 
additional arithmetics - rounding and are inprecise when 
comparing. I do not want to deal with it every time. But if there 
is any standard simple documentation that I could include into my 
own game documentation to avoid confusion and make everything 
consisten, I would like to know.

For now it seems that the only way to make it all simple is to 
use some kind of library to handle decimals for me, as I can't 
find any concise references on how to correctly use and 
understand floating points.