As this function is generic, it makes a big difference when it can be specialized for concrete sequences, like arrays or unsafe buffers.
This fixes a performance regression of String(decoding:as:), e.g. when constructing a String from a byte buffer.
_StringGuts is not meant to be an abstraction across all the forms a
String may take. It's meant to abstract the book-keeping and the
visitor is a parameterization over operations.
Extract slow paths into non-inlinable functions so that fast-paths can
be faster and we don't pay the large code bloat for the Unicode
parsers.
Some tests proactively extended to highlight UTF8View of multiple
kinds of Strings.
Drop append-related @inlinable annotations for String, StringGuts,
StringStorage, and the Views. Drop several for larger operations, such
as case conversion. Drop as many as we can from StringGuts for now.
This is a small performance win; mainly I'm interested in simplifying the code so that there are fewer weird corners for bugs to creep in. Nonetheless, it seems to be about 5% faster with the (fast, dumb) LCG generator.
Custom FixedWidthInteger types may not support this.
Introduce a new (non-public) FixedWidthInteger requirement for generating random values; implement it using &<</+ in the generic case, and specialize it using RandomNumberGenerator._fill(bytes) for the builtin types.
* Use the `__has_include` and `GRND_RANDOM` macros
* Use `getentropy` instead of `getrandom`
* Use `std::min` from the <algorithm> header
* Move `#if` out of the `_stdlib_random` function
* Use `getrandom` with "/dev/urandom" fallback
* Use `#pragma comment` to import "Bcrypt.lib"
* <https://docs.microsoft.com/en-us/cpp/preprocessor/comment-c-cpp>
* <https://clang.llvm.org/docs/UsersManual.html#microsoft-extensions>
* Use "/dev/urandom" instead of `SecRandomCopyBytes`
* Use `swift::StaticMutex` for shared "/dev/urandom"
* Add `getrandom_available`; use `O_CLOEXEC` flag
Add platform impl docs
Update copyrights
Fix docs
Add _stdlib_random test
Update _stdlib_random test
Add missing &
Notice about _stdlib_random
Fix docs
Guard on upperBound = 0
Test full range of 8 bit integers
Remove some gyb
Clean up integerRangeTest
Remove FixedWidthInteger constraint
Use arc4random universally
Fix randomElement
Constrain shuffle to RandomAccessCollection
warning instead of error
Move Apple's implementation
Fix failing test on 32 bit systems
Re-wrote the inner memcpy loops so that they can be vectorized.
Also added a few inline(__always).
Since we removed some @inlineable attributes this string-append code is not code generated in the client anymore.
The code generation in the stdlib binary is different because all the precondition checks are not folded away.
Using explicit loop control statements instead of for-in-range removes the precondition-overhead for those time critical memcpy loops.
* [stdlib] Revise documentation for new random APIs
* [stdlib] Fix constraints on random integer generation
* [test] Isolate failing Random test
* [benchmark] Add benchmarks for new random APIs
Fix Float80 test
Value type generators
random -> randomElement
Fix some docs
One more doc fix
Doc fixes & bool fix
Use computed over explicit
* Remove refs to Countable ranges
* Add `_stdlib_random` for more platforms
* Use `getrandom` (if available) for Android, Cygwin
* Reorder the `_stdlib_random` functions
* Also include <features.h> on Linux
* Add `#error TODO` in `_stdlib_random` for Windows
* Colon after Fatal Error
Performance improvement for Random
gybify ranges
Fix typo in 'basic random numbers'
Add _stdlib_random as a testable method
Switch to generic constraints
Hopefully link against bcrypt
Fix some implementation details
1. Uniform distribution is now uniform
2. Apply Jens' method for uniform floats
Fix a lineable attribute
Initial random api
Use C syscall for I/O
1. Fixed an issue where integers would would result in an infinite loop if they were unsigned, or signed integers always returning negative numbers.
2. Fixed an issue with Bool initialization
Add shuffle functions
Add documentation to Random API
Fix a few typos within the documentation
Fixes more typos
Also states that the range for floating points is from 0 to 1 inclusive
Update API to reflect mailing list discussions
Remove unnecessary import
Make sure not to return upperBound on Range
Use SecRandomCopyBytes on older macOS
Update API to match mailing list discussion, add tests
Added pick(_:) to collection
Added random(in:using:) to Randomizable
Added tests
Fix typo in Randomizable documentation
Rename pick to sampling
Move sampling below random
Update docs
Use new Libc naming
Fix Random.swift with new Libc naming
Remove sampling
gybify signed integer creation
Make FloatingPoint.random exclusive
Refactor {Closed}Range.random
Fix FloatingPoint initialization
Precondition getting a random number from range
Fix some doc typos
Make .random a function
Update API to reflect discussion
Make .random a function
Remove .random() in favor of .random(in:) for all numeric types
Fix compile errors
Clean up _stdlib_random
Cleanup around API
Remove `.random()` requirement from `Collection`
Use generators
Optimize shuffle()
Thread safety for /dev/urandom
Remove {Closed}Range<BinaryFloatingPoint>.random()
Add Collection random requirement
Refactor _stdlib_random
Remove whitespace changes
Clean linux shim
Add shuffle and more tests
Provide finishing tests and suggestions
Remove refs to Countable ranges
Revert to checking if T is > UInt64
