[ruby-core:115871] [Ruby master Feature#20080] Implement #begin_and_end method on Range

Issue #20080 has been updated by stuyam (Stuart Yamartino).


@Dan0042 great idea! At first I was against this because I thought it would make deconstruction harder but it actually wouldn't because deconstruction would work the same. I was thinking the second value if deconstructed would be an array like `[2, true]` but that would only be if you used a star `*` during deconstruction. I'm liking this...
```ruby
a = (1..2).bounds  #=> [1,2]
b = (1...2).bounds #=> [1,2,true]

Range.new(*a)      #=> 1..2
Range.new(*b)      #=> 1...2

start_num, end_num = a #=> start_num = 1, end_num = 2
start_num, end_num, excluded_end = a #=> start_num = 1, end_num = 2, excluded_end = nil
start_num, end_num = b #=> start_num = 1, end_num = 2
start_num, end_num, excluded_end = b #=> start_num = 1, end_num = 2, excluded_end = true
start_num, *remaining = b #=> start_num = 1, remaining = [2, true]
```

My only thought then is should there be an option to always include `exclude_end?` even when it is false like `(1..2).bounds(true) #=> [1,2,false]` so you would get `false` rather than `nil` in the array deconstruction example above.

----------------------------------------
Feature #20080: Implement #begin_and_end method on Range
https://bugs.ruby-lang.org/issues/20080#change-105828

* Author: stuyam (Stuart Yamartino)
* Status: Open
* Priority: Normal
----------------------------------------
Followup Reference: #20027 

This feature request is to implement a method called `#begin_and_end` on `Range` that returns an array of the first and last value stored in a range:
```ruby
(1..300).begin_and_end #=> [1, 300]

first, last = (300..1).begin_and_end
first #=> 300
last #=> 1
```
I believe this would be a great addition to Ranges as they are often used to pass around a single object used to hold endpoints, and this allows easier retrieval of those endpoints.
This would allow easier deconstruction into start and end values using array deconstruction as well as a simpler way to serialize to a more primitive object such as an array for database storage.
This implementation was suggested by @mame in my initial feature suggestion regarding range deconstruction: https://bugs.ruby-lang.org/issues/20027

This implementation would work similar to how `#minmax` works where it returns an array of two numbers, however the difference is that `#minmax` doesn't work with reverse ranges as @Dan0042 pointed out in the link above:
```ruby
(1..42).minmax #=> [1, 42]
(42..1).minmax #=> [nil, nil]
```





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