Constants.swift

#if os(Linux)
import CoreFoundation
#else
import Foundation
#endif

/// A boolean to see if the system is littleEndian
let isLitteEndian = CFByteOrderGetCurrent() == Int(CFByteOrderLittleEndian.rawValue)
/// Constant for the file id length
let FileIdLength = 4
/// Type aliases
public typealias Byte = UInt8
public typealias UOffset = UInt32
public typealias SOffset = Int32
public typealias VOffset = UInt16
/// Maximum size for a buffer
public let FlatBufferMaxSize = UInt32.max << ((MemoryLayout<SOffset>.size * 8 - 1) - 1)

/// Protocol that confirms all the numbers
///
/// Scalar is used to confirm all the numbers that can be represented in a FlatBuffer. It's used to write/read from the buffer.
public protocol Scalar: Equatable {
    associatedtype NumericValue
    var convertedEndian: NumericValue { get }
}

extension Scalar where Self: FixedWidthInteger {
    /// Converts the value from BigEndian to LittleEndian
    ///
    /// Converts values to little endian on machines that work with BigEndian, however this is NOT TESTED yet.
    public var convertedEndian: NumericValue {
        if isLitteEndian { return self as! Self.NumericValue }
        fatalError("This is not tested! please report an issue on the offical flatbuffers repo")
    }
}

extension Double: Scalar {
    public typealias NumericValue = UInt64
    
    public var convertedEndian: UInt64 {
        if isLitteEndian { return self.bitPattern }
        return self.bitPattern.littleEndian
    }
}

extension Float32: Scalar {
    public typealias NumericValue = UInt32
    
    public var convertedEndian: UInt32 {
        if isLitteEndian { return self.bitPattern }
        return self.bitPattern.littleEndian
    }
}

extension Int: Scalar {
    public typealias NumericValue = Int
}

extension Int8: Scalar {
    public typealias NumericValue = Int8
}

extension Int16: Scalar {
    public typealias NumericValue = Int16
}

extension Int32: Scalar {
    public typealias NumericValue = Int32
}

extension Int64: Scalar {
    public typealias NumericValue = Int64
}

extension UInt8: Scalar {
    public typealias NumericValue = UInt8
}

extension UInt16: Scalar {
    public typealias NumericValue = UInt16
}

extension UInt32: Scalar {
    public typealias NumericValue = UInt32
}

extension UInt64: Scalar {
    public typealias NumericValue = UInt64
}