[swift-evolution] [Draft] Target-specific CChar

[Dmitri Gribenko]

On Wed, Mar 2, 2016 at 11:03 AM, William Dillon <william at housedillon.com> wrote:
> It does violate the principle of least astonishment, but we should
> acknowledge that the implementation-specific nature of C's char signedness
> is making code *less* portable, not more -- because the same code can mean
> different things on different platforms.  Reflecting the same in Swift makes
> Swift code less portable, too.
>
> Dmitri
>
> That is a fair point, and I agree for the most part.  However, It is my
> intent and expectation that the use of CChar would be limited to the margins
> where C APIs are imported.  Once values become a part of Swift (and used in
> places outside of the C interface) they should have been cast into a pure
> Swift type (such as UInt8, Int8, Int, etc).

True, but how can you cast a CChar portably into UInt8 or Int8?  Only
via the bitPattern initializer, because the regular initializer will
trap on values outside of the 0..<128 range on signed platforms or
unsigned platforms.

Dmitri

-- 
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