// BinaryIntegerExtensions.swift - Copyright 2023 SwifterSwift
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// MARK: - Properties
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public extension BinaryInteger {
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/// SwifterSwift: The raw bytes of the integer.
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///
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/// var number = Int16(-128)
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/// print(number.bytes)
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/// // prints "[255, 128]"
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///
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var bytes: [UInt8] {
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var result = [UInt8]()
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result.reserveCapacity(MemoryLayout<Self>.size)
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var value = self
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for _ in 0..<MemoryLayout<Self>.size {
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result.append(UInt8(truncatingIfNeeded: value))
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value >>= 8
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}
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return result.reversed()
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}
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}
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// MARK: - Initializers
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public extension BinaryInteger {
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/// SwifterSwift: Creates a `BinaryInteger` from a raw byte representation.
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///
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/// var number = Int16(bytes: [0xFF, 0b1111_1101])
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/// print(number!)
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/// // prints "-3"
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///
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/// - Parameter bytes: An array of bytes representing the value of the integer.
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init?(bytes: [UInt8]) {
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// https://stackoverflow.com/a/43518567/9506784
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precondition(bytes.count <= MemoryLayout<Self>.size,
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"Integer with a \(bytes.count) byte binary representation of '\(bytes.map { String($0, radix: 2) }.joined(separator: " "))' overflows when stored into a \(MemoryLayout<Self>.size) byte '\(Self.self)'")
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var value: Self = 0
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for byte in bytes {
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value <<= 8
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value |= Self(byte)
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}
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self.init(exactly: value)
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}
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}
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