Issue #13166 has been updated by jzakiya (Jabari Zakiya).


This is a comparison of real code I have in a gem that is optimized for CRuby and JRuby.
JRuby allows you to use Java byte-arrays, which is both more memory efficient than the
CRuby version (I can create bigger arrays), but its much, much faster in JRuby than using 
**Array** in JRuby, here as an array of boolean (1|0) values.

An equivalent construction in CRuby can have similar advantages in mem/speed advantages.

```
    case RUBY
    when "jruby"
      def array_check(n,v)  # catch out-of-memory errors on array creation
        Java::byte[n].new rescue return
      end
      .....
      .....
    else
      def array_check(n,v)  # catch out-of-memory errors on array creation
        Array.new(n,v) rescue return  # return an array or nil
      end
      .....
      .....
   end

```

----------------------------------------
Feature #13166: Feature Request: Byte Arrays for Ruby 3
https://bugs.ruby-lang.org/issues/13166#change-63987

* Author: jzakiya (Jabari Zakiya)
* Status: Feedback
* Priority: Normal
* Assignee: 
* Target version: 
----------------------------------------
I do a lot of numerically intensive applications.
In many instances I use arrays that contain boolean data (true|false or 1|0) values.

When I create such an array like:

`data = Array.new(size, value)` or just  `data = Array.new(size)`

is it correct that the default memory unit size is that of the cpu, i.e. (32|64)-bit?

Since almost all modern cpus are byte addressable, I want to optimally use their system memory 
by being able to explicitly create arrays of byte addressable elements.

For these use cases, this wlll allow my apps to extend their memory use capacity, instead
of wasting 31|63 bit of memory on 32|64 bit cpus systems just to store a boolean value.

To be clear, I am not talking about storing "strings" or "chars" but addessable 8-bit number elements.

I have not seen this capability documented in Ruby, thus I request this feature be added to
Ruby 3, and propose the following syntax that will be backwards compatible (non conflicting).

```ruby
data = Array8.new(size, value)
```

Having explicit addressable byte arrays not only will increase memory use compactness of many
applications, this compactness will directly contribute to the Ruby 3x3 goal for performance
by allowing more data to be held entirely in cache memory when possible.

Thanks in advance for its consideratoin.




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