Introduce checking of ConcurrentValue conformances:
- For structs, check that each stored property conforms to ConcurrentValue
- For enums, check that each associated value conforms to ConcurrentValue
- For classes, check that each stored property is immutable and conforms
to ConcurrentValue
Because all of the stored properties / associated values need to be
visible for this check to work, limit ConcurrentValue conformances to
be in the same source file as the type definition.
This checking can be disabled by conforming to a new marker protocol,
UnsafeConcurrentValue, that refines ConcurrentValue.
UnsafeConcurrentValue otherwise his no specific meaning. This allows
both "I know what I'm doing" for types that manage concurrent access
themselves as well as enabling retroactive conformance, both of which
are fundamentally unsafe but also quite necessary.
The bulk of this change ended up being to the standard library, because
all conformances of standard library types to the ConcurrentValue
protocol needed to be sunk down into the standard library so they
would benefit from the checking above. There were numerous little
mistakes in the initial pass through the stsandard library types that
have now been corrected.
The "Result" type is expected to have no overhead when used.
This requires the member functions to be inlinable.
Which is probably okay for library evolution, because it's unlikely that those methods change in an incompatible way.
* Revise the Unicode scalar/Character properties
* Minor revisions to `compactMapValues` docs.
* Add documentation for AdditiveArithmetic, revise Numeric
* Apply minor style updates to count(where:).
* Revise string interpolation docs.
- Convert table of interpolation examples to a list of examples. Tables
aren't supported by Swift markup, so this wouldn't render properly in
Xcode or on the web.
- Add a description of what a user must implement in a custom
string interpolation type to get the behavior they want.
* Revise isMultiple(of:) docs.
- In particular, add emphasis to mathematical symbols and equations to
match how we document such things elsewhere.
- I'm using asterisks for single symbols, and underscores for equations
because it's easier to read in-source when you don't have to escape
multiplication within emphasis.
* Add some abstracts to the SIMD vector types.
- Adds a dictionary of spelled out numbers. Only numbers < 10
should be spelled out according to editorial.
- Adds abstracts to some of the basic members.
- Includes parameter descriptions for the xyzw properties and inits,
but not for the unlabeled initializers. Combined with the protocol
extension method abstracts, this should complete coverage of the concrete
types.
