Changed the implementation to this:
public var size: Int { return _sizeof(self._metatype) }
public var stride: Int { return _strideof(self._metatype) }
public var alignment: Int { return _alignof(self._metatype) }
public static var size: Int { return _sizeof(T.metatype) }
public static var stride: Int { return _strideof(T.metatype) }
public static var alignment: Int { return _alignof(T.metatype) }
Where the internal functions are based on current swift implementation except
that instead of T.Type it would be better to use AnyMetatype.
internal func _sizeof(_ metatype: AnyMetatype) -> Int {
return Int(Builtin.sizeof(metatype))
}
internal func _strideof(_ metatype: AnyMetatype) -> Int {
return Int(Builtin.strideof_nonzero(metatype))
}
internal func _alignof(_ metatype: AnyMetatype) -> Int {
return Int(Builtin.alignof(metatype))
}
I can’t test this because current sizeof, strideof and alignof are using T.Type
where something like this doesn’t work:
sizeof(Int.self) // 8
sizeof(CustomStringConvertible.self) // 40
sizeof(Int.self as CustomStringConvertible.Type) // Error
That said I can only assume that the buildin function will return the correct
value for the provided metatype.
let x = Int // equals Type<Int>.sharedInstance
x.size // 8
let y = Type<CustomStringConvertible>.cast(x)
y?.size // should be 8 as well
size and alignment would work analogically.
Type<T>.size // always returns the size of T
--
Adrian Zubarev
Sent with Airmail
Am 15. Juli 2016 um 19:05:56, Anton Zhilin ([email protected]) schrieb:
Next, I’d like to remind you of my
size,
stride,
align concerns. Consider this example:
let x = Type<Int>()
let y = Type<CustomStringConvertible>(casting: x)!
x.size //=> 8
y.size //=> 8 or 40?
I think that
y.size should be 8, because we are dynamically checking size of particular
instance
y, which refers to specific subtype of
CustomStringConvertible.
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