Language features like erasing concrete metatype
values are also left for the future. Still, baby steps.
The singleton ordinary metatype for existential types
is still potentially useful; we allow it to be written
as P.Protocol.
I've been somewhat cavalier in making code accept
AnyMetatypeType instead of a more specific type, and
it's likely that a number of these places can and
should be more restrictive.
When T is an existential type, parse T.Type as an
ExistentialMetatypeType instead of a MetatypeType.
An existential metatype is the formal type
\exists t:P . (t.Type)
whereas the ordinary metatype is the formal type
(\exists t:P . t).Type
which is singleton. Our inability to express that
difference was leading to an ever-increasing cascade
of hacks where information is shadily passed behind
the scenes in order to make various operations with
static members of protocols work correctly.
This patch takes the first step towards fixing that
by splitting out existential metatypes and giving
them a pointer representation. Eventually, we will
need them to be able to carry protocol witness tables
Swift SVN r15716
Use the ``init() -> T?`` return type syntax we introduced for whole-object initializers, and limit the scope of initializer failure to @objc initializers; we don't need to be able to initiate initializer failure from Swift for 1.0.
Swift SVN r15703
We won't have any types where copying has an effect on the bit pattern (except for blocks, which need special handling anyway), and copy_value having a result makes optimizations more complex, so remove it.
Swift SVN r15640
This will be a signal to ARC optimization, RVO, and other lifetime-affecting optimizations that they should not shorten the lifetime of a value past a certain point. We need this for C pointer bridging. This adds the instruction, but does not add any knowledge of it to the ARC optimizers.
Swift SVN r15601
In Cocoa selectors, "by" is often used before an action, i.e.,
URLByAppendingPathExtension:
characterRangeByExtendingPosition:inDirection:
dateByAddingComponents:toDate:options:
Dropping the preposition doesn't make the argument name better.
Swift SVN r15417
Building the field type vector is potentially expensive and the vector isn't needed unless we do reflectiony things to a type, so let's use a lazy accessor. Make room for it, but don't populate it yet, so we can deal with fallout from the metadata layout change.
Swift SVN r15194
Focus on the immediate problem of handling arguments. Describe the desired user model followed by the necessary language features to support the user model using library implicit conversions.
Swift SVN r15161
Loosen the restrictions on open_existential_ref to also allow it to
refer to an existential metatype. When it does, open_existential_ref
returns the metatype for the opened archetype.
Swift SVN r15113
This reverts commit r14488, since we're demoting 'type' back to a plain old identifier.
We could consider reallowing 'type' as a contextual keyword here, but from talking to Jordan he was OK with just reverting this functionality.
Swift SVN r14931
