//
/*
"Miscellaneous Utility Library" Software Licence

Version 1.0

Copyright (c) 2004-2008 Jon Skeet and Marc Gravell.
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.

3. The end-user documentation included with the redistribution, if
any, must include the following acknowledgment:

"This product includes software developed by Jon Skeet
and Marc Gravell. Contact skeet@pobox.com, or see
http://www.pobox.com/~skeet/)."

Alternately, this acknowledgment may appear in the software itself,
if and wherever such third-party acknowledgments normally appear.

4. The name "Miscellaneous Utility Library" must not be used to endorse
or promote products derived from this software without prior written
permission. For written permission, please contact skeet@pobox.com.

5. Products derived from this software may not be called
"Miscellaneous Utility Library", nor may "Miscellaneous Utility Library"
appear in their name, without prior written permission of Jon Skeet.

THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED 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 JON SKEET 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.
*/

using System;
using System.Runtime.InteropServices;

// ReSharper disable once CheckNamespace
namespace GameDevWare.Serialization.MessagePack
{
	/// <summary>
	///     Equivalent of System.BitConverter, but with either endianness.
	/// </summary>
	internal abstract class EndianBitConverter
	{
		#region Endianness of this converter

		/// <summary>
		///     Indicates the byte order ("endianess") in which data is converted using this class.
		/// </summary>
		/// <remarks>
		///     Different computer architectures store data using different byte orders. "Big-endian"
		///     means the most significant byte is on the left end of a word. "Little-endian" means the
		///     most significant byte is on the right end of a word.
		/// </remarks>
		/// <returns>true if this converter is little-endian, false otherwise.</returns>
		public abstract bool IsLittleEndian();

		/// <summary>
		///     Indicates the byte order ("endianess") in which data is converted using this class.
		/// </summary>
		public abstract Endianness Endianness { get; }

		#endregion

		#region Factory properties

		private static readonly LittleEndianBitConverter little = new LittleEndianBitConverter();

		/// <summary>
		///     Returns a little-endian bit converter instance. The same instance is
		///     always returned.
		/// </summary>
		public static LittleEndianBitConverter Little
		{
			get { return little; }
		}

		private static readonly BigEndianBitConverter big = new BigEndianBitConverter();

		/// <summary>
		///     Returns a big-endian bit converter instance. The same instance is
		///     always returned.
		/// </summary>
		public static BigEndianBitConverter Big
		{
			get { return big; }
		}

		#endregion

		#region Double/primitive conversions

		/// <summary>
		///     Converts the specified double-precision floating point number to a
		///     64-bit signed integer. Note: the endianness of this converter does not
		///     affect the returned value.
		/// </summary>
		/// <param name="value">The number to convert. </param>
		/// <returns>A 64-bit signed integer whose value is equivalent to value.</returns>
		public long DoubleToInt64Bits(double value)
		{
			return BitConverter.DoubleToInt64Bits(value);
		}

		/// <summary>
		///     Converts the specified 64-bit signed integer to a double-precision
		///     floating point number. Note: the endianness of this converter does not
		///     affect the returned value.
		/// </summary>
		/// <param name="value">The number to convert. </param>
		/// <returns>A double-precision floating point number whose value is equivalent to value.</returns>
		public double Int64BitsToDouble(long value)
		{
			return BitConverter.Int64BitsToDouble(value);
		}

		/// <summary>
		///     Converts the specified single-precision floating point number to a
		///     32-bit signed integer. Note: the endianness of this converter does not
		///     affect the returned value.
		/// </summary>
		/// <param name="value">The number to convert. </param>
		/// <returns>A 32-bit signed integer whose value is equivalent to value.</returns>
		public int SingleToInt32Bits(float value)
		{
			return new Int32SingleUnion(value).AsInt32;
		}

		/// <summary>
		///     Converts the specified 32-bit signed integer to a single-precision floating point
		///     number. Note: the endianness of this converter does not
		///     affect the returned value.
		/// </summary>
		/// <param name="value">The number to convert. </param>
		/// <returns>A single-precision floating point number whose value is equivalent to value.</returns>
		public float Int32BitsToSingle(int value)
		{
			return new Int32SingleUnion(value).AsSingle;
		}

		#endregion

		#region To(PrimitiveType) conversions

		/// <summary>
		///     Returns a Boolean value converted from one byte at a specified position in a byte array.
		/// </summary>
		/// <param name="value">An array of bytes.</param>
		/// <param name="startIndex">The starting position within value.</param>
		/// <returns>true if the byte at startIndex in value is nonzero; otherwise, false.</returns>
		public bool ToBoolean(byte[] value, int startIndex)
		{
			CheckByteArgument(value, startIndex, 1);
			return BitConverter.ToBoolean(value, startIndex);
		}

		/// <summary>
		///     Returns a Unicode character converted from two bytes at a specified position in a byte array.
		/// </summary>
		/// <param name="value">An array of bytes.</param>
		/// <param name="startIndex">The starting position within value.</param>
		/// <returns>A character formed by two bytes beginning at startIndex.</returns>
		public char ToChar(byte[] value, int startIndex)
		{
			return unchecked((char) (CheckedFromBytes(value, startIndex, 2)));
		}

		/// <summary>
		///     Returns a double-precision floating point number converted from eight bytes
		///     at a specified position in a byte array.
		/// </summary>
		/// <param name="value">An array of bytes.</param>
		/// <param name="startIndex">The starting position within value.</param>
		/// <returns>A double precision floating point number formed by eight bytes beginning at startIndex.</returns>
		public double ToDouble(byte[] value, int startIndex)
		{
			return Int64BitsToDouble(ToInt64(value, startIndex));
		}

		/// <summary>
		///     Returns a single-precision floating point number converted from four bytes
		///     at a specified position in a byte array.
		/// </summary>
		/// <param name="value">An array of bytes.</param>
		/// <param name="startIndex">The starting position within value.</param>
		/// <returns>A single precision floating point number formed by four bytes beginning at startIndex.</returns>
		public float ToSingle(byte[] value, int startIndex)
		{
			return Int32BitsToSingle(ToInt32(value, startIndex));
		}

		/// <summary>
		///     Returns a 16-bit signed integer converted from two bytes at a specified position in a byte array.
		/// </summary>
		/// <param name="value">An array of bytes.</param>
		/// <param name="startIndex">The starting position within value.</param>
		/// <returns>A 16-bit signed integer formed by two bytes beginning at startIndex.</returns>
		public short ToInt16(byte[] value, int startIndex)
		{
			return unchecked((short) (CheckedFromBytes(value, startIndex, 2)));
		}

		/// <summary>
		///     Returns a 32-bit signed integer converted from four bytes at a specified position in a byte array.
		/// </summary>
		/// <param name="value">An array of bytes.</param>
		/// <param name="startIndex">The starting position within value.</param>
		/// <returns>A 32-bit signed integer formed by four bytes beginning at startIndex.</returns>
		public int ToInt32(byte[] value, int startIndex)
		{
			return unchecked((int) (CheckedFromBytes(value, startIndex, 4)));
		}

		/// <summary>
		///     Returns a 64-bit signed integer converted from eight bytes at a specified position in a byte array.
		/// </summary>
		/// <param name="value">An array of bytes.</param>
		/// <param name="startIndex">The starting position within value.</param>
		/// <returns>A 64-bit signed integer formed by eight bytes beginning at startIndex.</returns>
		public long ToInt64(byte[] value, int startIndex)
		{
			return CheckedFromBytes(value, startIndex, 8);
		}

		/// <summary>
		///     Returns a 16-bit unsigned integer converted from two bytes at a specified position in a byte array.
		/// </summary>
		/// <param name="value">An array of bytes.</param>
		/// <param name="startIndex">The starting position within value.</param>
		/// <returns>A 16-bit unsigned integer formed by two bytes beginning at startIndex.</returns>
		public ushort ToUInt16(byte[] value, int startIndex)
		{
			return unchecked((ushort) (CheckedFromBytes(value, startIndex, 2)));
		}

		/// <summary>
		///     Returns a 32-bit unsigned integer converted from four bytes at a specified position in a byte array.
		/// </summary>
		/// <param name="value">An array of bytes.</param>
		/// <param name="startIndex">The starting position within value.</param>
		/// <returns>A 32-bit unsigned integer formed by four bytes beginning at startIndex.</returns>
		public uint ToUInt32(byte[] value, int startIndex)
		{
			return unchecked((uint) (CheckedFromBytes(value, startIndex, 4)));
		}

		/// <summary>
		///     Returns a 64-bit unsigned integer converted from eight bytes at a specified position in a byte array.
		/// </summary>
		/// <param name="value">An array of bytes.</param>
		/// <param name="startIndex">The starting position within value.</param>
		/// <returns>A 64-bit unsigned integer formed by eight bytes beginning at startIndex.</returns>
		public ulong ToUInt64(byte[] value, int startIndex)
		{
			return unchecked((ulong) (CheckedFromBytes(value, startIndex, 8)));
		}

		/// <summary>
		///     Checks the given argument for validity.
		/// </summary>
		/// <param name="value">The byte array passed in</param>
		/// <param name="startIndex">The start index passed in</param>
		/// <param name="bytesRequired">The number of bytes required</param>
		/// <exception cref="ArgumentNullException">value is a null reference</exception>
		/// <exception cref="ArgumentOutOfRangeException">
		///     startIndex is less than zero or greater than the length of value minus bytesRequired.
		/// </exception>
		private static void CheckByteArgument(byte[] value, int startIndex, int bytesRequired)
		{
			if (value == null)
			{
				throw new ArgumentNullException("value");
			}
			if (startIndex < 0 || startIndex > value.Length - bytesRequired)
			{
				throw new ArgumentOutOfRangeException("startIndex");
			}
		}

		/// <summary>
		///     Checks the arguments for validity before calling FromBytes
		///     (which can therefore assume the arguments are valid).
		/// </summary>
		/// <param name="value">The bytes to convert after checking</param>
		/// <param name="startIndex">The index of the first byte to convert</param>
		/// <param name="bytesToConvert">The number of bytes to convert</param>
		/// <returns></returns>
		private long CheckedFromBytes(byte[] value, int startIndex, int bytesToConvert)
		{
			CheckByteArgument(value, startIndex, bytesToConvert);
			return FromBytes(value, startIndex, bytesToConvert);
		}

		/// <summary>
		///     Convert the given number of bytes from the given array, from the given start
		///     position, into a long, using the bytes as the least significant part of the long.
		///     By the time this is called, the arguments have been checked for validity.
		/// </summary>
		/// <param name="value">The bytes to convert</param>
		/// <param name="startIndex">The index of the first byte to convert</param>
		/// <param name="bytesToConvert">The number of bytes to use in the conversion</param>
		/// <returns>The converted number</returns>
		protected abstract long FromBytes(byte[] value, int startIndex, int bytesToConvert);

		#endregion

		#region ToString conversions

		/// <summary>
		///     Returns a String converted from the elements of a byte array.
		/// </summary>
		/// <param name="value">An array of bytes.</param>
		/// <remarks>All the elements of value are converted.</remarks>
		/// <returns>
		///     A String of hexadecimal pairs separated by hyphens, where each pair
		///     represents the corresponding element in value; for example, "7F-2C-4A".
		/// </returns>
		public static string ToString(byte[] value)
		{
			return BitConverter.ToString(value);
		}

		/// <summary>
		///     Returns a String converted from the elements of a byte array starting at a specified array position.
		/// </summary>
		/// <param name="value">An array of bytes.</param>
		/// <param name="startIndex">The starting position within value.</param>
		/// <remarks>The elements from array position startIndex to the end of the array are converted.</remarks>
		/// <returns>
		///     A String of hexadecimal pairs separated by hyphens, where each pair
		///     represents the corresponding element in value; for example, "7F-2C-4A".
		/// </returns>
		public static string ToString(byte[] value, int startIndex)
		{
			return BitConverter.ToString(value, startIndex);
		}

		/// <summary>
		///     Returns a String converted from a specified number of bytes at a specified position in a byte array.
		/// </summary>
		/// <param name="value">An array of bytes.</param>
		/// <param name="startIndex">The starting position within value.</param>
		/// <param name="length">The number of bytes to convert.</param>
		/// <remarks>The length elements from array position startIndex are converted.</remarks>
		/// <returns>
		///     A String of hexadecimal pairs separated by hyphens, where each pair
		///     represents the corresponding element in value; for example, "7F-2C-4A".
		/// </returns>
		public static string ToString(byte[] value, int startIndex, int length)
		{
			return BitConverter.ToString(value, startIndex, length);
		}

		#endregion

		#region	Decimal conversions

		/// <summary>
		///     Returns a decimal value converted from sixteen bytes
		///     at a specified position in a byte array.
		/// </summary>
		/// <param name="value">An array of bytes.</param>
		/// <param name="startIndex">The starting position within value.</param>
		/// <returns>A decimal  formed by sixteen bytes beginning at startIndex.</returns>
		public decimal ToDecimal(byte[] value, int startIndex)
		{
			// HACK: This always assumes four parts, each in their own endianness,
			// starting with the first part at the start of the byte array.
			// On the other hand, there's no real format specified...
			var parts = new int[4];
			for (var i = 0; i < 4; i++)
			{
				parts[i] = ToInt32(value, startIndex + i*4);
			}
			return new decimal(parts);
		}

		/// <summary>
		///     Returns the specified decimal value as an array of bytes.
		/// </summary>
		/// <param name="value">The number to convert.</param>
		/// <returns>An array of bytes with length 16.</returns>
		public byte[] GetBytes(decimal value)
		{
			var bytes = new byte[16];
			var parts = decimal.GetBits(value);
			for (var i = 0; i < 4; i++)
			{
				CopyBytesImpl(parts[i], 4, bytes, i*4);
			}
			return bytes;
		}

		/// <summary>
		///     Copies the specified decimal value into the specified byte array,
		///     beginning at the specified index.
		/// </summary>
		/// <param name="value">A character to convert.</param>
		/// <param name="buffer">The byte array to copy the bytes into</param>
		/// <param name="index">The first index into the array to copy the bytes into</param>
		public void CopyBytes(decimal value, byte[] buffer, int index)
		{
			var parts = decimal.GetBits(value);
			for (var i = 0; i < 4; i++)
			{
				CopyBytesImpl(parts[i], 4, buffer, i*4 + index);
			}
		}

		#endregion

		#region GetBytes conversions

		/// <summary>
		///     Returns an array with the given number of bytes formed
		///     from the least significant bytes of the specified value.
		///     This is used to implement the other GetBytes methods.
		/// </summary>
		/// <param name="value">The value to get bytes for</param>
		/// <param name="bytes">The number of significant bytes to return</param>
		private byte[] GetBytes(long value, int bytes)
		{
			var buffer = new byte[bytes];
			CopyBytes(value, bytes, buffer, 0);
			return buffer;
		}

		/// <summary>
		///     Returns the specified Boolean value as an array of bytes.
		/// </summary>
		/// <param name="value">A Boolean value.</param>
		/// <returns>An array of bytes with length 1.</returns>
		public byte[] GetBytes(bool value)
		{
			return BitConverter.GetBytes(value);
		}

		/// <summary>
		///     Returns the specified Unicode character value as an array of bytes.
		/// </summary>
		/// <param name="value">A character to convert.</param>
		/// <returns>An array of bytes with length 2.</returns>
		public byte[] GetBytes(char value)
		{
			return GetBytes(value, 2);
		}

		/// <summary>
		///     Returns the specified double-precision floating point value as an array of bytes.
		/// </summary>
		/// <param name="value">The number to convert.</param>
		/// <returns>An array of bytes with length 8.</returns>
		public byte[] GetBytes(double value)
		{
			return GetBytes(DoubleToInt64Bits(value), 8);
		}

		/// <summary>
		///     Returns the specified 16-bit signed integer value as an array of bytes.
		/// </summary>
		/// <param name="value">The number to convert.</param>
		/// <returns>An array of bytes with length 2.</returns>
		public byte[] GetBytes(short value)
		{
			return GetBytes(value, 2);
		}

		/// <summary>
		///     Returns the specified 32-bit signed integer value as an array of bytes.
		/// </summary>
		/// <param name="value">The number to convert.</param>
		/// <returns>An array of bytes with length 4.</returns>
		public byte[] GetBytes(int value)
		{
			return GetBytes(value, 4);
		}

		/// <summary>
		///     Returns the specified 64-bit signed integer value as an array of bytes.
		/// </summary>
		/// <param name="value">The number to convert.</param>
		/// <returns>An array of bytes with length 8.</returns>
		public byte[] GetBytes(long value)
		{
			return GetBytes(value, 8);
		}

		/// <summary>
		///     Returns the specified single-precision floating point value as an array of bytes.
		/// </summary>
		/// <param name="value">The number to convert.</param>
		/// <returns>An array of bytes with length 4.</returns>
		public byte[] GetBytes(float value)
		{
			return GetBytes(SingleToInt32Bits(value), 4);
		}

		/// <summary>
		///     Returns the specified 16-bit unsigned integer value as an array of bytes.
		/// </summary>
		/// <param name="value">The number to convert.</param>
		/// <returns>An array of bytes with length 2.</returns>
		public byte[] GetBytes(ushort value)
		{
			return GetBytes(value, 2);
		}

		/// <summary>
		///     Returns the specified 32-bit unsigned integer value as an array of bytes.
		/// </summary>
		/// <param name="value">The number to convert.</param>
		/// <returns>An array of bytes with length 4.</returns>
		public byte[] GetBytes(uint value)
		{
			return GetBytes(value, 4);
		}

		/// <summary>
		///     Returns the specified 64-bit unsigned integer value as an array of bytes.
		/// </summary>
		/// <param name="value">The number to convert.</param>
		/// <returns>An array of bytes with length 8.</returns>
		public byte[] GetBytes(ulong value)
		{
			return GetBytes(unchecked((long) value), 8);
		}

		#endregion

		#region CopyBytes conversions

		/// <summary>
		///     Copies the given number of bytes from the least-specific
		///     end of the specified value into the specified byte array, beginning
		///     at the specified index.
		///     This is used to implement the other CopyBytes methods.
		/// </summary>
		/// <param name="value">The value to copy bytes for</param>
		/// <param name="bytes">The number of significant bytes to copy</param>
		/// <param name="buffer">The byte array to copy the bytes into</param>
		/// <param name="index">The first index into the array to copy the bytes into</param>
		private void CopyBytes(long value, int bytes, byte[] buffer, int index)
		{
			if (buffer == null)
			{
				throw new ArgumentNullException("buffer", "Byte array must not be null");
			}
			if (buffer.Length < index + bytes)
			{
				throw new ArgumentOutOfRangeException("Buffer not big enough for value");
			}
			CopyBytesImpl(value, bytes, buffer, index);
		}

		/// <summary>
		///     Copies the given number of bytes from the least-specific
		///     end of the specified value into the specified byte array, beginning
		///     at the specified index.
		///     This must be implemented in concrete derived classes, but the implementation
		///     may assume that the value will fit into the buffer.
		/// </summary>
		/// <param name="value">The value to copy bytes for</param>
		/// <param name="bytes">The number of significant bytes to copy</param>
		/// <param name="buffer">The byte array to copy the bytes into</param>
		/// <param name="index">The first index into the array to copy the bytes into</param>
		protected abstract void CopyBytesImpl(long value, int bytes, byte[] buffer, int index);

		/// <summary>
		///     Copies the specified Boolean value into the specified byte array,
		///     beginning at the specified index.
		/// </summary>
		/// <param name="value">A Boolean value.</param>
		/// <param name="buffer">The byte array to copy the bytes into</param>
		/// <param name="index">The first index into the array to copy the bytes into</param>
		public void CopyBytes(bool value, byte[] buffer, int index)
		{
			CopyBytes(value ? 1 : 0, 1, buffer, index);
		}

		/// <summary>
		///     Copies the specified Unicode character value into the specified byte array,
		///     beginning at the specified index.
		/// </summary>
		/// <param name="value">A character to convert.</param>
		/// <param name="buffer">The byte array to copy the bytes into</param>
		/// <param name="index">The first index into the array to copy the bytes into</param>
		public void CopyBytes(char value, byte[] buffer, int index)
		{
			CopyBytes(value, 2, buffer, index);
		}

		/// <summary>
		///     Copies the specified double-precision floating point value into the specified byte array,
		///     beginning at the specified index.
		/// </summary>
		/// <param name="value">The number to convert.</param>
		/// <param name="buffer">The byte array to copy the bytes into</param>
		/// <param name="index">The first index into the array to copy the bytes into</param>
		public void CopyBytes(double value, byte[] buffer, int index)
		{
			CopyBytes(DoubleToInt64Bits(value), 8, buffer, index);
		}

		/// <summary>
		///     Copies the specified 16-bit signed integer value into the specified byte array,
		///     beginning at the specified index.
		/// </summary>
		/// <param name="value">The number to convert.</param>
		/// <param name="buffer">The byte array to copy the bytes into</param>
		/// <param name="index">The first index into the array to copy the bytes into</param>
		public void CopyBytes(short value, byte[] buffer, int index)
		{
			CopyBytes(value, 2, buffer, index);
		}

		/// <summary>
		///     Copies the specified 32-bit signed integer value into the specified byte array,
		///     beginning at the specified index.
		/// </summary>
		/// <param name="value">The number to convert.</param>
		/// <param name="buffer">The byte array to copy the bytes into</param>
		/// <param name="index">The first index into the array to copy the bytes into</param>
		public void CopyBytes(int value, byte[] buffer, int index)
		{
			CopyBytes(value, 4, buffer, index);
		}

		/// <summary>
		///     Copies the specified 64-bit signed integer value into the specified byte array,
		///     beginning at the specified index.
		/// </summary>
		/// <param name="value">The number to convert.</param>
		/// <param name="buffer">The byte array to copy the bytes into</param>
		/// <param name="index">The first index into the array to copy the bytes into</param>
		public void CopyBytes(long value, byte[] buffer, int index)
		{
			CopyBytes(value, 8, buffer, index);
		}

		/// <summary>
		///     Copies the specified single-precision floating point value into the specified byte array,
		///     beginning at the specified index.
		/// </summary>
		/// <param name="value">The number to convert.</param>
		/// <param name="buffer">The byte array to copy the bytes into</param>
		/// <param name="index">The first index into the array to copy the bytes into</param>
		public void CopyBytes(float value, byte[] buffer, int index)
		{
			CopyBytes(SingleToInt32Bits(value), 4, buffer, index);
		}

		/// <summary>
		///     Copies the specified 16-bit unsigned integer value into the specified byte array,
		///     beginning at the specified index.
		/// </summary>
		/// <param name="value">The number to convert.</param>
		/// <param name="buffer">The byte array to copy the bytes into</param>
		/// <param name="index">The first index into the array to copy the bytes into</param>
		public void CopyBytes(ushort value, byte[] buffer, int index)
		{
			CopyBytes(value, 2, buffer, index);
		}

		/// <summary>
		///     Copies the specified 32-bit unsigned integer value into the specified byte array,
		///     beginning at the specified index.
		/// </summary>
		/// <param name="value">The number to convert.</param>
		/// <param name="buffer">The byte array to copy the bytes into</param>
		/// <param name="index">The first index into the array to copy the bytes into</param>
		public void CopyBytes(uint value, byte[] buffer, int index)
		{
			CopyBytes(value, 4, buffer, index);
		}

		/// <summary>
		///     Copies the specified 64-bit unsigned integer value into the specified byte array,
		///     beginning at the specified index.
		/// </summary>
		/// <param name="value">The number to convert.</param>
		/// <param name="buffer">The byte array to copy the bytes into</param>
		/// <param name="index">The first index into the array to copy the bytes into</param>
		public void CopyBytes(ulong value, byte[] buffer, int index)
		{
			CopyBytes(unchecked((long) value), 8, buffer, index);
		}

		#endregion

		#region Private struct used for Single/Int32 conversions

		/// <summary>
		///     Union used solely for the equivalent of DoubleToInt64Bits and vice versa.
		/// </summary>
		[StructLayout(LayoutKind.Explicit)]
		private struct Int32SingleUnion
		{
			/// <summary>
			///     Int32 version of the value.
			/// </summary>
			[FieldOffset(0)] private readonly int i;

			/// <summary>
			///     Single version of the value.
			/// </summary>
			[FieldOffset(0)] private readonly float f;

			/// <summary>
			///     Creates an instance representing the given integer.
			/// </summary>
			/// <param name="i">The integer value of the new instance.</param>
			internal Int32SingleUnion(int i)
			{
				this.f = 0; // Just to keep the compiler happy
				this.i = i;
			}

			/// <summary>
			///     Creates an instance representing the given floating point number.
			/// </summary>
			/// <param name="f">The floating point value of the new instance.</param>
			internal Int32SingleUnion(float f)
			{
				this.i = 0; // Just to keep the compiler happy
				this.f = f;
			}

			/// <summary>
			///     Returns the value of the instance as an integer.
			/// </summary>
			internal int AsInt32
			{
				get { return i; }
			}

			/// <summary>
			///     Returns the value of the instance as a floating point number.
			/// </summary>
			internal float AsSingle
			{
				get { return f; }
			}
		}

		#endregion
	}
}
