Avoid using accidental public API (#47)

Motivation:

NIOs underscored Base64 module accidentally leaked some public API as
extensions on `String`. We shouldn't use these.

Modifications:

- Vend base64 encoding
- Use it instead of NIOs API

Result:

Avoid using accidentally public API

NOTICES.txt

@@ -0,0 +1,25 @@
+                          The gRPC Swift Project
+                          ======================
+
+Copyright 2024 The gRPC Swift Project
+
+The gRPC Swift project licenses this file to you under the Apache License,
+version 2.0 (the "License"); you may not use this file except in compliance
+with the License. You may obtain a copy of the License at:
+
+  https://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+License for the specific language governing permissions and limitations
+under the License.
+
+-------------------------------------------------------------------------------
+
+This product uses derivations of swift-extras/swift-extras-base64 'Base64.swift'.
+
+  * LICENSE (Apache License 2.0):
+    * https://github.com/swift-extras/swift-extras-base64/blob/main/LICENSE
+  * HOMEPAGE:
+    * https://github.com/swift-extras/swift-extras-base64

Sources/GRPCNIOTransportCore/GRPCStreamStateMachine.swift

@@ -1866,7 +1866,7 @@ extension Metadata {
     for header in headers {
       if header.name.hasSuffix("-bin") {
         do {
-          let decodedBinary = try header.value.base64Decoded()
+          let decodedBinary = try Base64.decode(string: header.value)
           metadata.addBinary(decodedBinary, forKey: header.name)
         } catch {
           metadata.addString(header.value, forKey: header.name)

Sources/GRPCNIOTransportCore/Internal/Base64.swift

@@ -0,0 +1,732 @@
+/*
+ * Copyright 2023, gRPC Authors All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+// This base64 implementation is heavily inspired by:
+
+// https://github.com/lemire/fastbase64/blob/a2e0967dfcb8f0129ea45b9b24cc410e4cac117f/src/chromiumbase64.c
+/*
+ Copyright (c) 2015-2016, Wojciech Muła, Alfred Klomp,  Daniel Lemire
+ (Unless otherwise stated in the source code)
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are
+ met:
+
+ 1. Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+
+ 2. Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in the
+ documentation and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+// https://github.com/client9/stringencoders/blob/e1448a9415f4ebf6f559c86718193ba067cbb99d/src/modp_b64.c
+/*
+ The MIT License (MIT)
+
+ Copyright (c) 2016 Nick Galbreath
+
+ Permission is hereby granted, free of charge, to any person obtaining a copy
+ of this software and associated documentation files (the "Software"), to deal
+ in the Software without restriction, including without limitation the rights
+ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the Software is
+ furnished to do so, subject to the following conditions:
+
+ The above copyright notice and this permission notice shall be included in all
+ copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ SOFTWARE.
+ */
+
+// swift-format-ignore: DontRepeatTypeInStaticProperties
+enum Base64 {
+  struct DecodingOptions: OptionSet {
+    internal let rawValue: UInt
+    internal init(rawValue: UInt) { self.rawValue = rawValue }
+
+    internal static let base64UrlAlphabet = DecodingOptions(rawValue: UInt(1 << 0))
+    internal static let omitPaddingCharacter = DecodingOptions(rawValue: UInt(1 << 1))
+  }
+
+  enum DecodingError: Error, Equatable {
+    case invalidLength
+    case invalidCharacter(UInt8)
+    case unexpectedPaddingCharacter
+    case unexpectedEnd
+  }
+
+  static func encode<Buffer: Collection>(bytes: Buffer) -> String where Buffer.Element == UInt8 {
+    guard !bytes.isEmpty else {
+      return ""
+    }
+
+    // In Base64, 3 bytes become 4 output characters, and we pad to the
+    // nearest multiple of four.
+    let base64StringLength = ((bytes.count + 2) / 3) * 4
+    let alphabet = Base64.encodeBase64
+
+    return String(customUnsafeUninitializedCapacity: base64StringLength) { backingStorage in
+      var input = bytes.makeIterator()
+      var offset = 0
+      while let firstByte = input.next() {
+        let secondByte = input.next()
+        let thirdByte = input.next()
+
+        backingStorage[offset] = Base64.encode(alphabet: alphabet, firstByte: firstByte)
+        backingStorage[offset + 1] = Base64.encode(
+          alphabet: alphabet,
+          firstByte: firstByte,
+          secondByte: secondByte
+        )
+        backingStorage[offset + 2] = Base64.encode(
+          alphabet: alphabet,
+          secondByte: secondByte,
+          thirdByte: thirdByte
+        )
+        backingStorage[offset + 3] = Base64.encode(alphabet: alphabet, thirdByte: thirdByte)
+        offset += 4
+      }
+      return offset
+    }
+  }
+
+  static func decode(
+    string encoded: String,
+    options: DecodingOptions = []
+  ) throws -> [UInt8] {
+    let decoded = try encoded.utf8.withContiguousStorageIfAvailable {
+      (characterPointer) -> [UInt8] in
+      guard characterPointer.count > 0 else {
+        return []
+      }
+
+      let outputLength = ((characterPointer.count + 3) / 4) * 3
+
+      return try characterPointer.withMemoryRebound(to: UInt8.self) { (input) -> [UInt8] in
+        try [UInt8](unsafeUninitializedCapacity: outputLength) { output, length in
+          try Self._decodeChromium(from: input, into: output, length: &length, options: options)
+        }
+      }
+    }
+
+    if decoded != nil {
+      return decoded!
+    }
+
+    var encoded = encoded
+    encoded.makeContiguousUTF8()
+    return try Self.decode(string: encoded, options: options)
+  }
+
+  private static func _decodeChromium(
+    from inBuffer: UnsafeBufferPointer<UInt8>,
+    into outBuffer: UnsafeMutableBufferPointer<UInt8>,
+    length: inout Int,
+    options: DecodingOptions = []
+  ) throws {
+    let remaining = inBuffer.count % 4
+    switch (options.contains(.omitPaddingCharacter), remaining) {
+    case (false, 1...):
+      throw DecodingError.invalidLength
+    case (true, 1):
+      throw DecodingError.invalidLength
+    default:
+      // everythin alright so far
+      break
+    }
+
+    let outputLength = ((inBuffer.count + 3) / 4) * 3
+    let fullchunks = remaining == 0 ? inBuffer.count / 4 - 1 : inBuffer.count / 4
+    guard outBuffer.count >= outputLength else {
+      preconditionFailure("Expected the out buffer to be at least as long as outputLength")
+    }
+
+    try Self.withUnsafeDecodingTablesAsBufferPointers(options: options) { d0, d1, d2, d3 in
+      var outIndex = 0
+      if fullchunks > 0 {
+        for chunk in 0 ..< fullchunks {
+          let inIndex = chunk * 4
+          let a0 = inBuffer[inIndex]
+          let a1 = inBuffer[inIndex + 1]
+          let a2 = inBuffer[inIndex + 2]
+          let a3 = inBuffer[inIndex + 3]
+          var x: UInt32 = d0[Int(a0)] | d1[Int(a1)] | d2[Int(a2)] | d3[Int(a3)]
+
+          if x >= Self.badCharacter {
+            // TODO: Inspect characters here better
+            throw DecodingError.invalidCharacter(inBuffer[inIndex])
+          }
+
+          withUnsafePointer(to: &x) { ptr in
+            ptr.withMemoryRebound(to: UInt8.self, capacity: 4) { newPtr in
+              outBuffer[outIndex] = newPtr[0]
+              outBuffer[outIndex + 1] = newPtr[1]
+              outBuffer[outIndex + 2] = newPtr[2]
+              outIndex += 3
+            }
+          }
+        }
+      }
+
+      // inIndex is the first index in the last chunk
+      let inIndex = fullchunks * 4
+      let a0 = inBuffer[inIndex]
+      let a1 = inBuffer[inIndex + 1]
+      var a2: UInt8?
+      var a3: UInt8?
+      if inIndex + 2 < inBuffer.count, inBuffer[inIndex + 2] != Self.encodePaddingCharacter {
+        a2 = inBuffer[inIndex + 2]
+      }
+      if inIndex + 3 < inBuffer.count, inBuffer[inIndex + 3] != Self.encodePaddingCharacter {
+        a3 = inBuffer[inIndex + 3]
+      }
+
+      var x: UInt32 = d0[Int(a0)] | d1[Int(a1)] | d2[Int(a2 ?? 65)] | d3[Int(a3 ?? 65)]
+      if x >= Self.badCharacter {
+        // TODO: Inspect characters here better
+        throw DecodingError.invalidCharacter(inBuffer[inIndex])
+      }
+
+      withUnsafePointer(to: &x) { ptr in
+        ptr.withMemoryRebound(to: UInt8.self, capacity: 4) { newPtr in
+          outBuffer[outIndex] = newPtr[0]
+          outIndex += 1
+          if a2 != nil {
+            outBuffer[outIndex] = newPtr[1]
+            outIndex += 1
+          }
+          if a3 != nil {
+            outBuffer[outIndex] = newPtr[2]
+            outIndex += 1
+          }
+        }
+      }
+
+      length = outIndex
+    }
+  }
+
+  private static func withUnsafeDecodingTablesAsBufferPointers<R>(
+    options: Base64.DecodingOptions,
+    _ body: (
+      UnsafeBufferPointer<UInt32>, UnsafeBufferPointer<UInt32>, UnsafeBufferPointer<UInt32>,
+      UnsafeBufferPointer<UInt32>
+    ) throws -> R
+  ) rethrows -> R {
+    let decoding0 = options.contains(.base64UrlAlphabet) ? Self.decoding0url : Self.decoding0
+    let decoding1 = options.contains(.base64UrlAlphabet) ? Self.decoding1url : Self.decoding1
+    let decoding2 = options.contains(.base64UrlAlphabet) ? Self.decoding2url : Self.decoding2
+    let decoding3 = options.contains(.base64UrlAlphabet) ? Self.decoding3url : Self.decoding3
+
+    assert(decoding0.count == 256)
+    assert(decoding1.count == 256)
+    assert(decoding2.count == 256)
+    assert(decoding3.count == 256)
+
+    return try decoding0.withUnsafeBufferPointer { (d0) -> R in
+      try decoding1.withUnsafeBufferPointer { (d1) -> R in
+        try decoding2.withUnsafeBufferPointer { (d2) -> R in
+          try decoding3.withUnsafeBufferPointer { (d3) -> R in
+            try body(d0, d1, d2, d3)
+          }
+        }
+      }
+    }
+  }
+
+  private static let encodePaddingCharacter: UInt8 = 61
+
+  private static let encodeBase64: [UInt8] = [
+    UInt8(ascii: "A"), UInt8(ascii: "B"), UInt8(ascii: "C"), UInt8(ascii: "D"),
+    UInt8(ascii: "E"), UInt8(ascii: "F"), UInt8(ascii: "G"), UInt8(ascii: "H"),
+    UInt8(ascii: "I"), UInt8(ascii: "J"), UInt8(ascii: "K"), UInt8(ascii: "L"),
+    UInt8(ascii: "M"), UInt8(ascii: "N"), UInt8(ascii: "O"), UInt8(ascii: "P"),
+    UInt8(ascii: "Q"), UInt8(ascii: "R"), UInt8(ascii: "S"), UInt8(ascii: "T"),
+    UInt8(ascii: "U"), UInt8(ascii: "V"), UInt8(ascii: "W"), UInt8(ascii: "X"),
+    UInt8(ascii: "Y"), UInt8(ascii: "Z"), UInt8(ascii: "a"), UInt8(ascii: "b"),
+    UInt8(ascii: "c"), UInt8(ascii: "d"), UInt8(ascii: "e"), UInt8(ascii: "f"),
+    UInt8(ascii: "g"), UInt8(ascii: "h"), UInt8(ascii: "i"), UInt8(ascii: "j"),
+    UInt8(ascii: "k"), UInt8(ascii: "l"), UInt8(ascii: "m"), UInt8(ascii: "n"),
+    UInt8(ascii: "o"), UInt8(ascii: "p"), UInt8(ascii: "q"), UInt8(ascii: "r"),
+    UInt8(ascii: "s"), UInt8(ascii: "t"), UInt8(ascii: "u"), UInt8(ascii: "v"),
+    UInt8(ascii: "w"), UInt8(ascii: "x"), UInt8(ascii: "y"), UInt8(ascii: "z"),
+    UInt8(ascii: "0"), UInt8(ascii: "1"), UInt8(ascii: "2"), UInt8(ascii: "3"),
+    UInt8(ascii: "4"), UInt8(ascii: "5"), UInt8(ascii: "6"), UInt8(ascii: "7"),
+    UInt8(ascii: "8"), UInt8(ascii: "9"), UInt8(ascii: "+"), UInt8(ascii: "/"),
+  ]
+
+  private static func encode(alphabet: [UInt8], firstByte: UInt8) -> UInt8 {
+    let index = firstByte >> 2
+    return alphabet[Int(index)]
+  }
+
+  private static func encode(alphabet: [UInt8], firstByte: UInt8, secondByte: UInt8?) -> UInt8 {
+    var index = (firstByte & 0b00000011) << 4
+    if let secondByte = secondByte {
+      index += (secondByte & 0b11110000) >> 4
+    }
+    return alphabet[Int(index)]
+  }
+
+  private static func encode(alphabet: [UInt8], secondByte: UInt8?, thirdByte: UInt8?) -> UInt8 {
+    guard let secondByte = secondByte else {
+      // No second byte means we are just emitting padding.
+      return Base64.encodePaddingCharacter
+    }
+    var index = (secondByte & 0b00001111) << 2
+    if let thirdByte = thirdByte {
+      index += (thirdByte & 0b11000000) >> 6
+    }
+    return alphabet[Int(index)]
+  }
+
+  private static func encode(alphabet: [UInt8], thirdByte: UInt8?) -> UInt8 {
+    guard let thirdByte = thirdByte else {
+      // No third byte means just padding.
+      return Base64.encodePaddingCharacter
+    }
+    let index = thirdByte & 0b00111111
+    return alphabet[Int(index)]
+  }
+
+  private static let badCharacter: UInt32 = 0x01FF_FFFF
+
+  private static let decoding0: [UInt32] = [
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x0000_00F8, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x0000_00FC,
+    0x0000_00D0, 0x0000_00D4, 0x0000_00D8, 0x0000_00DC, 0x0000_00E0, 0x0000_00E4,
+    0x0000_00E8, 0x0000_00EC, 0x0000_00F0, 0x0000_00F4, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x0000_0000,
+    0x0000_0004, 0x0000_0008, 0x0000_000C, 0x0000_0010, 0x0000_0014, 0x0000_0018,
+    0x0000_001C, 0x0000_0020, 0x0000_0024, 0x0000_0028, 0x0000_002C, 0x0000_0030,
+    0x0000_0034, 0x0000_0038, 0x0000_003C, 0x0000_0040, 0x0000_0044, 0x0000_0048,
+    0x0000_004C, 0x0000_0050, 0x0000_0054, 0x0000_0058, 0x0000_005C, 0x0000_0060,
+    0x0000_0064, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x0000_0068, 0x0000_006C, 0x0000_0070, 0x0000_0074, 0x0000_0078,
+    0x0000_007C, 0x0000_0080, 0x0000_0084, 0x0000_0088, 0x0000_008C, 0x0000_0090,
+    0x0000_0094, 0x0000_0098, 0x0000_009C, 0x0000_00A0, 0x0000_00A4, 0x0000_00A8,
+    0x0000_00AC, 0x0000_00B0, 0x0000_00B4, 0x0000_00B8, 0x0000_00BC, 0x0000_00C0,
+    0x0000_00C4, 0x0000_00C8, 0x0000_00CC, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+  ]
+
+  private static let decoding1: [UInt32] = [
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x0000_E003, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x0000_F003,
+    0x0000_4003, 0x0000_5003, 0x0000_6003, 0x0000_7003, 0x0000_8003, 0x0000_9003,
+    0x0000_A003, 0x0000_B003, 0x0000_C003, 0x0000_D003, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x0000_0000,
+    0x0000_1000, 0x0000_2000, 0x0000_3000, 0x0000_4000, 0x0000_5000, 0x0000_6000,
+    0x0000_7000, 0x0000_8000, 0x0000_9000, 0x0000_A000, 0x0000_B000, 0x0000_C000,
+    0x0000_D000, 0x0000_E000, 0x0000_F000, 0x0000_0001, 0x0000_1001, 0x0000_2001,
+    0x0000_3001, 0x0000_4001, 0x0000_5001, 0x0000_6001, 0x0000_7001, 0x0000_8001,
+    0x0000_9001, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x0000_A001, 0x0000_B001, 0x0000_C001, 0x0000_D001, 0x0000_E001,
+    0x0000_F001, 0x0000_0002, 0x0000_1002, 0x0000_2002, 0x0000_3002, 0x0000_4002,
+    0x0000_5002, 0x0000_6002, 0x0000_7002, 0x0000_8002, 0x0000_9002, 0x0000_A002,
+    0x0000_B002, 0x0000_C002, 0x0000_D002, 0x0000_E002, 0x0000_F002, 0x0000_0003,
+    0x0000_1003, 0x0000_2003, 0x0000_3003, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+  ]
+
+  private static let decoding2: [UInt32] = [
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x0080_0F00, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x00C0_0F00,
+    0x0000_0D00, 0x0040_0D00, 0x0080_0D00, 0x00C0_0D00, 0x0000_0E00, 0x0040_0E00,
+    0x0080_0E00, 0x00C0_0E00, 0x0000_0F00, 0x0040_0F00, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x0000_0000,
+    0x0040_0000, 0x0080_0000, 0x00C0_0000, 0x0000_0100, 0x0040_0100, 0x0080_0100,
+    0x00C0_0100, 0x0000_0200, 0x0040_0200, 0x0080_0200, 0x00C0_0200, 0x0000_0300,
+    0x0040_0300, 0x0080_0300, 0x00C0_0300, 0x0000_0400, 0x0040_0400, 0x0080_0400,
+    0x00C0_0400, 0x0000_0500, 0x0040_0500, 0x0080_0500, 0x00C0_0500, 0x0000_0600,
+    0x0040_0600, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x0080_0600, 0x00C0_0600, 0x0000_0700, 0x0040_0700, 0x0080_0700,
+    0x00C0_0700, 0x0000_0800, 0x0040_0800, 0x0080_0800, 0x00C0_0800, 0x0000_0900,
+    0x0040_0900, 0x0080_0900, 0x00C0_0900, 0x0000_0A00, 0x0040_0A00, 0x0080_0A00,
+    0x00C0_0A00, 0x0000_0B00, 0x0040_0B00, 0x0080_0B00, 0x00C0_0B00, 0x0000_0C00,
+    0x0040_0C00, 0x0080_0C00, 0x00C0_0C00, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+  ]
+
+  private static let decoding3: [UInt32] = [
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x003E_0000, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x003F_0000,
+    0x0034_0000, 0x0035_0000, 0x0036_0000, 0x0037_0000, 0x0038_0000, 0x0039_0000,
+    0x003A_0000, 0x003B_0000, 0x003C_0000, 0x003D_0000, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x0000_0000,
+    0x0001_0000, 0x0002_0000, 0x0003_0000, 0x0004_0000, 0x0005_0000, 0x0006_0000,
+    0x0007_0000, 0x0008_0000, 0x0009_0000, 0x000A_0000, 0x000B_0000, 0x000C_0000,
+    0x000D_0000, 0x000E_0000, 0x000F_0000, 0x0010_0000, 0x0011_0000, 0x0012_0000,
+    0x0013_0000, 0x0014_0000, 0x0015_0000, 0x0016_0000, 0x0017_0000, 0x0018_0000,
+    0x0019_0000, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x001A_0000, 0x001B_0000, 0x001C_0000, 0x001D_0000, 0x001E_0000,
+    0x001F_0000, 0x0020_0000, 0x0021_0000, 0x0022_0000, 0x0023_0000, 0x0024_0000,
+    0x0025_0000, 0x0026_0000, 0x0027_0000, 0x0028_0000, 0x0029_0000, 0x002A_0000,
+    0x002B_0000, 0x002C_0000, 0x002D_0000, 0x002E_0000, 0x002F_0000, 0x0030_0000,
+    0x0031_0000, 0x0032_0000, 0x0033_0000, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+  ]
+
+  private static let decoding0url: [UInt32] = [
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 0
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 6
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 12
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 18
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 24
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 30
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 36
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x0000_00F8, 0x01FF_FFFF, 0x01FF_FFFF,  // 42
+    0x0000_00D0, 0x0000_00D4, 0x0000_00D8, 0x0000_00DC, 0x0000_00E0, 0x0000_00E4,  // 48
+    0x0000_00E8, 0x0000_00EC, 0x0000_00F0, 0x0000_00F4, 0x01FF_FFFF, 0x01FF_FFFF,  // 54
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x0000_0000,  // 60
+    0x0000_0004, 0x0000_0008, 0x0000_000C, 0x0000_0010, 0x0000_0014, 0x0000_0018,  // 66
+    0x0000_001C, 0x0000_0020, 0x0000_0024, 0x0000_0028, 0x0000_002C, 0x0000_0030,  // 72
+    0x0000_0034, 0x0000_0038, 0x0000_003C, 0x0000_0040, 0x0000_0044, 0x0000_0048,  // 78
+    0x0000_004C, 0x0000_0050, 0x0000_0054, 0x0000_0058, 0x0000_005C, 0x0000_0060,  // 84
+    0x0000_0064, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x0000_00FC,  // 90
+    0x01FF_FFFF, 0x0000_0068, 0x0000_006C, 0x0000_0070, 0x0000_0074, 0x0000_0078,
+    0x0000_007C, 0x0000_0080, 0x0000_0084, 0x0000_0088, 0x0000_008C, 0x0000_0090,
+    0x0000_0094, 0x0000_0098, 0x0000_009C, 0x0000_00A0, 0x0000_00A4, 0x0000_00A8,
+    0x0000_00AC, 0x0000_00B0, 0x0000_00B4, 0x0000_00B8, 0x0000_00BC, 0x0000_00C0,
+    0x0000_00C4, 0x0000_00C8, 0x0000_00CC, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+  ]
+
+  private static let decoding1url: [UInt32] = [
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 0
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 6
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 12
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 18
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 24
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 30
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 36
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x0000_E003, 0x01FF_FFFF, 0x01FF_FFFF,  // 42
+    0x0000_4003, 0x0000_5003, 0x0000_6003, 0x0000_7003, 0x0000_8003, 0x0000_9003,  // 48
+    0x0000_A003, 0x0000_B003, 0x0000_C003, 0x0000_D003, 0x01FF_FFFF, 0x01FF_FFFF,  // 54
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x0000_0000,  // 60
+    0x0000_1000, 0x0000_2000, 0x0000_3000, 0x0000_4000, 0x0000_5000, 0x0000_6000,  // 66
+    0x0000_7000, 0x0000_8000, 0x0000_9000, 0x0000_A000, 0x0000_B000, 0x0000_C000,  // 72
+    0x0000_D000, 0x0000_E000, 0x0000_F000, 0x0000_0001, 0x0000_1001, 0x0000_2001,  // 78
+    0x0000_3001, 0x0000_4001, 0x0000_5001, 0x0000_6001, 0x0000_7001, 0x0000_8001,  // 84
+    0x0000_9001, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x0000_F003,  // 90
+    0x01FF_FFFF, 0x0000_A001, 0x0000_B001, 0x0000_C001, 0x0000_D001, 0x0000_E001,
+    0x0000_F001, 0x0000_0002, 0x0000_1002, 0x0000_2002, 0x0000_3002, 0x0000_4002,
+    0x0000_5002, 0x0000_6002, 0x0000_7002, 0x0000_8002, 0x0000_9002, 0x0000_A002,
+    0x0000_B002, 0x0000_C002, 0x0000_D002, 0x0000_E002, 0x0000_F002, 0x0000_0003,
+    0x0000_1003, 0x0000_2003, 0x0000_3003, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+  ]
+
+  private static let decoding2url: [UInt32] = [
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 0
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 6
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 12
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 18
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 24
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 30
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 36
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x0080_0F00, 0x01FF_FFFF, 0x01FF_FFFF,  // 42
+    0x0000_0D00, 0x0040_0D00, 0x0080_0D00, 0x00C0_0D00, 0x0000_0E00, 0x0040_0E00,  // 48
+    0x0080_0E00, 0x00C0_0E00, 0x0000_0F00, 0x0040_0F00, 0x01FF_FFFF, 0x01FF_FFFF,  // 54
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x0000_0000,  // 60
+    0x0040_0000, 0x0080_0000, 0x00C0_0000, 0x0000_0100, 0x0040_0100, 0x0080_0100,  // 66
+    0x00C0_0100, 0x0000_0200, 0x0040_0200, 0x0080_0200, 0x00C0_0200, 0x0000_0300,  // 72
+    0x0040_0300, 0x0080_0300, 0x00C0_0300, 0x0000_0400, 0x0040_0400, 0x0080_0400,  // 78
+    0x00C0_0400, 0x0000_0500, 0x0040_0500, 0x0080_0500, 0x00C0_0500, 0x0000_0600,  // 84
+    0x0040_0600, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x00C0_0F00,  // 90
+    0x01FF_FFFF, 0x0080_0600, 0x00C0_0600, 0x0000_0700, 0x0040_0700, 0x0080_0700,
+    0x00C0_0700, 0x0000_0800, 0x0040_0800, 0x0080_0800, 0x00C0_0800, 0x0000_0900,
+    0x0040_0900, 0x0080_0900, 0x00C0_0900, 0x0000_0A00, 0x0040_0A00, 0x0080_0A00,
+    0x00C0_0A00, 0x0000_0B00, 0x0040_0B00, 0x0080_0B00, 0x00C0_0B00, 0x0000_0C00,
+    0x0040_0C00, 0x0080_0C00, 0x00C0_0C00, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+  ]
+
+  private static let decoding3url: [UInt32] = [
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 0
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 6
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 12
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 18
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 24
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 30
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,  // 36
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x003E_0000, 0x01FF_FFFF, 0x01FF_FFFF,  // 42
+    0x0034_0000, 0x0035_0000, 0x0036_0000, 0x0037_0000, 0x0038_0000, 0x0039_0000,  // 48
+    0x003A_0000, 0x003B_0000, 0x003C_0000, 0x003D_0000, 0x01FF_FFFF, 0x01FF_FFFF,  // 54
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x0000_0000,  // 60
+    0x0001_0000, 0x0002_0000, 0x0003_0000, 0x0004_0000, 0x0005_0000, 0x0006_0000,  // 66
+    0x0007_0000, 0x0008_0000, 0x0009_0000, 0x000A_0000, 0x000B_0000, 0x000C_0000,  // 72
+    0x000D_0000, 0x000E_0000, 0x000F_0000, 0x0010_0000, 0x0011_0000, 0x0012_0000,  // 78
+    0x0013_0000, 0x0014_0000, 0x0015_0000, 0x0016_0000, 0x0017_0000, 0x0018_0000,  // 84
+    0x0019_0000, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x003F_0000,  // 90
+    0x01FF_FFFF, 0x001A_0000, 0x001B_0000, 0x001C_0000, 0x001D_0000, 0x001E_0000,
+    0x001F_0000, 0x0020_0000, 0x0021_0000, 0x0022_0000, 0x0023_0000, 0x0024_0000,
+    0x0025_0000, 0x0026_0000, 0x0027_0000, 0x0028_0000, 0x0029_0000, 0x002A_0000,
+    0x002B_0000, 0x002C_0000, 0x002D_0000, 0x002E_0000, 0x002F_0000, 0x0030_0000,
+    0x0031_0000, 0x0032_0000, 0x0033_0000, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+    0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF, 0x01FF_FFFF,
+  ]
+}
+
+extension String {
+  /// This is a backport of a proposed String initializer that will allow writing directly into an uninitialized String's backing memory.
+  ///
+  /// As this API does not exist prior to 5.3 on Linux, or on older Apple platforms, we fake it out with a pointer and accept the extra copy.
+  init(
+    backportUnsafeUninitializedCapacity capacity: Int,
+    initializingUTF8With initializer: (_ buffer: UnsafeMutableBufferPointer<UInt8>) throws -> Int
+  ) rethrows {
+
+    // The buffer will store zero terminated C string
+    let buffer = UnsafeMutableBufferPointer<UInt8>.allocate(capacity: capacity + 1)
+    defer {
+      buffer.deallocate()
+    }
+
+    let initializedCount = try initializer(buffer)
+    precondition(initializedCount <= capacity, "Overran buffer in initializer!")
+
+    // add zero termination
+    buffer[initializedCount] = 0
+
+    self = String(cString: buffer.baseAddress!)
+  }
+
+  init(
+    customUnsafeUninitializedCapacity capacity: Int,
+    initializingUTF8With initializer: (_ buffer: UnsafeMutableBufferPointer<UInt8>) throws -> Int
+  ) rethrows {
+    if #available(macOS 11.0, iOS 14.0, tvOS 14.0, watchOS 7.0, *) {
+      try self.init(unsafeUninitializedCapacity: capacity, initializingUTF8With: initializer)
+    } else {
+      try self.init(
+        backportUnsafeUninitializedCapacity: capacity,
+        initializingUTF8With: initializer
+      )
+    }
+  }
+}