Arithmetic operator overloading result type should be the same as the operands

[jorgeluismireles]

Describe the bug

Arithmetic operations should remain associative and distributive. So A + B + C = D should be to valid in any case, to mention a simple example.

Current arithmetic operator overloading permits the result to be different from the operands. Problems:

• The user don't know what type the result would be.
• Associative rule and others will fails.
• Extra bugs (see the last code).

Inconsistencies were mentioned already here: #23177

Reproduction Steps

type Byte = u8
type String = string

pub fn (b1 Byte) + (b2 Byte) String {
	return '${u16(b1) + u16(b2)}'
}

fn main() {
	println('${Byte(255) + Byte(1) + Byte(2)}')
}

Expected Behavior

A Byte whatever the value, truncated or even as an error when operation does not apply.

Current Behavior

Running code...
Can't run code. The server returned an error:
code.v:9:13: error: infix expr: cannot use `Byte` (right expression) as `String`
    7 | 
    8 | fn main() {
    9 |     println('${Byte(255) + Byte(1) + Byte(2)}')
      |                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   10 | }
Exited with error status 1
Please try again.

Possible Solution

Force result type to be the same of the operands.

Additional Information/Context

More complications:

type Byte = u8

pub fn (b1 Byte) + (b2 Byte) string {
	return '${u16(b1) + u16(b2)}'
}

fn main() {
	println('${Byte(255) + Byte(1)}')
}

Produces C error:

Running code...
Can't run code. The server returned an error:
/tmp/v_60000/../../../../../../box/code.v:8: error: cannot convert 'struct string' to 'unsigned char'
builder error: 
==================
C error found. It should never happen, when compiling pure V code.
This is a V compiler bug, please report it using `v bug file.v`,
or goto https://github.com/vlang/v/issues/new/choose .
You can also use #help on Discord: https://discord.gg/vlang .
Exited with error status 1
Please try again.

V version

V 0.4.8 00148d1

Environment details (OS name and version, etc.)

https://play.vlang.io/p/0b6cc9e21c

https://play.vlang.io/p/b09d63132f

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_{Huly®: V_0.6-21631}

[spytheman]

Afaik that is a bug that only affects type aliases. Overriding operators on the non aliased types is checked and the types are required to be the same for the operands and for the result.