Why does golang only encode a string character in byte(uint8) and rune(int32)?

Question

go

Good afternoon.
Question with an example, we have:

charLine := "слово" 
fmt.Println(charLine) // кодирует кириллицу в по 2 байта на каждый символ. По дефолту тип элементов(символов) byte т.е. uint8

Question n1.
1) Why can't I explicitly specify what type of elements to use in a variable?
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Okay, let's go the other way. Slicing a text string:

sliceLine := []byte(charLine)
fmt.Println(sliceLine) // byte это алиас на тип uint8, т.е. сейчас видим бинарное представление данных, как сделано для типа string с приведением к строке. Делая срез мы можем указать какой тип использовать: uint8 или int32 (rune)

Question n2
Why for a slice, I can't specify the type uint16. For the Cyrillic alphabet, enough for the eyes. And then just as usual to bring from a number to a line with a standard string() function?
The question has some practical value. Let's say I'm a big miser :) and I'm sorry to allocate 4 bytes in memory for each character using rune. Therefore, I want to allocate only 2 bytes using uint16 (I think it makes no sense for a character to take into account sign bit => Cyrillic will fit), but golang does not understand me. Or I did it :)
Yes, uint8 (byte) does not suit the fact that it encodes Cyrillic by several bytes and it is not convenient to work with it as with an array of characters.

Answer 1

What are you actually trying to achieve with these actions?
When it comes to memory, Go's internal representation of strings is UTF-8. When you write charLine := "слово", you are specifying a UTF-8 string.
In Go, a string can be converted (back and forth) to only two types - to []byte and to []rune. []byte is a mutable copy of the bytes of the immutable string, []rune is the result of parsing the UTF-8 bytes of the string into 4-byte unicode codes.
The question why only these two, and not, say, []float, is meaningless. Because that's how language is made. If you need []uint16 - well, write your own converter, it's not difficult.
It's all described in the documentation here: golang.org/ref/spec#Conversions_to_and_from_a_stri...