[Pitch] 128 bit Integer Types

[tera]

@wadetregaskis

I think the main issue with that is that it turns trivial assignment into something that can crash, e.g. if you write powerLevel = 9001.

But that we have with normal ints, when you assign a big or negative value to, say, UInt8.

@wadetregaskis

You can try to work around it with bespoke setters that throw instead (not great ergonomics without additional language support), or you can just silently clamp the value (but doesn't make sense in many cases).

Unchecked exceptions could work great in this and similar cases.

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@Joe_Groff

If the field is Optional typed it could also use an out-of-range value to represent the nil case.

How can I make a 1 byte struct like Int8, and optional of it that doesn't add another byte?

struct Int7 { // one byte, values in -64 ... +63 range
    private var rawValue: Int8
    ...
} 
struct Int8x { // one byte, values in -127 ... +127 range
    private var rawValue: Int8
    ...
} 
var x: Optional<Int7> = .some(42)  // still one byte wanted!
var y: Optional<Int8x> = .some(42) // still one byte wanted!

Does it require compiler support?