AloneGame / Library / PackageCache / com.unity.collections / Unity.Collections / FixedList.tt

<#/*THIS IS A T4 FILE - see t4_text_templating.md for what it is and how to run codegen*/#>
<#@ template debug="True" #>
<#@ output extension=".gen.cs" encoding="utf-8" #>
<#@ assembly name="System.Core" #>
<#@ import namespace="System.Globalization" #>
<#@ import namespace="System.Security.Cryptography" #>

//------------------------------------------------------------------------------
// <auto-generated>
//     This code was generated by a tool.
//
//     TextTransform Samples/Packages/com.unity.collections/Unity.Collections/FixedList.tt
//
//     Changes to this file may cause incorrect behavior and will be lost if
//     the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

using System.Collections.Generic;
using System.Collections;
using System.Diagnostics;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System;
using Unity.Collections.LowLevel.Unsafe;
using Unity.Mathematics;
using UnityEngine.Internal;
using UnityEngine;
using Unity.Properties;

namespace Unity.Collections
{
    [GenerateTestsForBurstCompatibility(GenericTypeArguments = new [] { typeof(int), typeof(FixedBytes32Align8) })]
    [Serializable]
    internal struct FixedList<T,U>
    : INativeList<T>
    where T : unmanaged
    where U : unmanaged
    {
        [SerializeField] internal U data;

        internal ushort length
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            readonly get
            {
                unsafe
                {
                    fixed(void* ptr = &data)
                        return *((ushort*)ptr);
                }
            }

            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            set
            {
                unsafe
                {
                    fixed (void* ptr = &data)
                        *((ushort*)ptr) = value;
                }
            }
        }

        internal readonly unsafe byte* buffer
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            get
            {
                unsafe
                {
                    fixed (void* ptr = &data)
                        return ((byte*)ptr) + UnsafeUtility.SizeOf<ushort>();
                }
            }
        }

        /// <summary>
        /// The current number of items in this list.
        /// </summary>
        /// <value>The current number of items in this list.</value>
        [CreateProperty]
        public int Length
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            readonly get => length;

            set
            {
                FixedList.CheckResize<U,T>(value);
                length = (ushort)value;
            }
        }

        /// <summary>
        /// A property in order to display items in the Entity Inspector.
        /// </summary>
        [CreateProperty] IEnumerable<T> Elements => this.ToArray();

        /// <summary>
        /// Whether the list is empty.
        /// </summary>
        /// <value>True if this string has no characters or if the container has not been constructed.</value>
        public readonly bool IsEmpty
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            get => Length == 0;
        }

        internal readonly int LengthInBytes => Length * UnsafeUtility.SizeOf<T>();

        internal readonly unsafe byte* Buffer
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            get
            {
                return buffer + FixedList.PaddingBytes<T>();
            }
        }

        /// <summary>
        /// The number of elements that can fit in this list.
        /// </summary>
        /// <value>The number of elements that can fit in this list.</value>
        /// <remarks>The capacity of a FixedList cannot be changed. The setter is included only for conformity with <see cref="INativeList{T}"/>.</remarks>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if the new value does not match the current capacity.</exception>
        public int Capacity
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            readonly get
            {
                return FixedList.Capacity<U,T>();
            }

            set
            {
                CollectionHelper.CheckCapacityInRange(value, Length);
            }
        }

        /// <summary>
        /// The element at a given index.
        /// </summary>
        /// <param name="index">An index.</param>
        /// <value>The value to store at the index.</value>
        /// <exception cref="IndexOutOfRangeException">Thrown if the index is out of bounds.</exception>
        public T this[int index]
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            readonly get
            {
                CollectionHelper.CheckIndexInRange(index, length);
                unsafe
                {
                    return UnsafeUtility.ReadArrayElement<T>(Buffer, CollectionHelper.AssumePositive(index));
                }
            }

            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            set
            {
                CollectionHelper.CheckIndexInRange(index, length);
                unsafe
                {
                    UnsafeUtility.WriteArrayElement<T>(Buffer, CollectionHelper.AssumePositive(index), value);
                }
            }
        }

        /// <summary>
        /// Returns the element at a given index.
        /// </summary>
        /// <param name="index">An index.</param>
        /// <returns>A reference to the element at the index.</returns>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public ref T ElementAt(int index)
        {
            CollectionHelper.CheckIndexInRange(index, length);
            unsafe
            {
                return ref UnsafeUtility.ArrayElementAsRef<T>(Buffer, index);
            }
        }

        /// <summary>
        /// Returns the hash code of this list.
        /// </summary>
        /// <remarks>
        /// Only the content of the list (the bytes of the elements) are included in the hash. Any bytes beyond the length are not part of the hash.</remarks>
        /// <returns>The hash code of this list.</returns>
        public override int GetHashCode()
        {
            unsafe
            {
                return (int)CollectionHelper.Hash(Buffer, LengthInBytes);
            }
        }

        /// <summary>
        /// Appends an element to the end of this list. Increments the length by 1.
        /// </summary>
        /// <remarks>
        /// The same as <see cref="AddNoResize"/>. Included only for consistency with the other list types.
        /// If the element exceeds the capacity, throws cref="IndexOutOfRangeException", and the list is unchanged.
        /// </remarks>
        /// <param name="item">The element to append at the end of the list.</param>
        /// <exception cref="IndexOutOfRangeException">Thrown if the append exceeds the capacity.</exception>
        public void Add(in T item) => AddNoResize(in item);

        /// <summary>
        /// Appends elements from a buffer to the end of this list. Increments the length by the number of appended elements.
        /// </summary>
        /// <remarks>
        /// The same as <see cref="AddRangeNoResize"/>. Included only for consistency with the other list types.
        /// If the elements exceeds the capacity, throws cref="IndexOutOfRangeException", and the list is unchanged.
        /// </remarks>
        /// <param name="ptr">A buffer.</param>
        /// <param name="length">The number of elements from the buffer to append.</param>
        /// <exception cref="IndexOutOfRangeException">Thrown if the append exceeds the capacity.</exception>
        public unsafe void AddRange(void* ptr, int length) => AddRangeNoResize(ptr, length);

        /// <summary>
        /// Appends an element to the end of this list. Increments the length by 1.
        /// </summary>
        /// <remarks>
        /// If the element exceeds the capacity, throws cref="IndexOutOfRangeException", and the list is unchanged.
        /// </remarks>
        /// <param name="item">The element to append at the end of the list.</param>
        /// <exception cref="IndexOutOfRangeException">Thrown if the append exceeds the capacity.</exception>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void AddNoResize(in T item)
        {
            this[Length++] = item;
        }

        /// <summary>
        /// Appends elements from a buffer to the end of this list. Increments the length by the number of appended elements.
        /// </summary>
        /// <remarks>
        /// If the elements exceeds the capacity, throws cref="IndexOutOfRangeException", and the list is unchanged.
        /// </remarks>
        /// <param name="ptr">A buffer.</param>
        /// <param name="length">The number of elements from the buffer to append.</param>
        /// <exception cref="IndexOutOfRangeException">Thrown if the append exceeds the capacity.</exception>
        public unsafe void AddRangeNoResize(void* ptr, int length)
        {
            var idx = Length;
            Length += length;
            UnsafeUtility.MemCpy((T*)Buffer + idx, ptr, UnsafeUtility.SizeOf<T>() * length);
        }

        /// <summary>
        /// Appends value count times to the end of this list.
        /// </summary>
        /// <remarks>
        /// If the elements exceeds the capacity, throws cref="IndexOutOfRangeException", and the list is unchanged.
        /// </remarks>
        /// <param name="value">The value to add to the end of this list.</param>
        /// <param name="count">The number of times to replicate the value.</param>
        /// <exception cref="IndexOutOfRangeException">Thrown if the append exceeds the capacity.</exception>
        public unsafe void AddReplicate(in T value, int count)
        {
            var idx = Length;
            Length += count;
            fixed (T* ptr = &value)
                UnsafeUtility.MemCpyReplicate((T*)Buffer + idx, ptr, UnsafeUtility.SizeOf<T>(), count);
        }

        /// <summary>
        /// Sets the length to 0.
        /// </summary>
        /// <remarks> Does *not* zero out the bytes.</remarks>
        public void Clear()
        {
            Length = 0;
        }

        /// <summary>
        /// Shifts elements toward the end of this list, increasing its length.
        /// </summary>
        /// <remarks>
        /// Right-shifts elements in the list so as to create 'free' slots at the beginning or in the middle.
        ///
        /// The length is increased by `end - begin`.
        ///
        /// If `end` equals `begin`, the method does nothing.
        ///
        /// The element at index `begin` will be copied to index `end`, the element at index `begin + 1` will be copied to `end + 1`, and so forth.
        ///
        /// The indexes `begin` up to `end` are not cleared: they will contain whatever values they held prior.
        /// </remarks>
        /// <param name="begin">The index of the first element that will be shifted up.</param>
        /// <param name="end">The index where the first shifted element will end up.</param>
        /// <exception cref="IndexOutOfRangeException">Thrown if the new length exceeds the capacity.</exception>
        public void InsertRangeWithBeginEnd(int begin, int end)
        {
            int items = end - begin;
            if(items < 1)
                return;
            int itemsToCopy = length - begin;
            Length += items;
            if(itemsToCopy < 1)
                return;
            int bytesToCopy = itemsToCopy * UnsafeUtility.SizeOf<T>();
            unsafe
            {
                byte *b = Buffer;
                byte *dest = b + end * UnsafeUtility.SizeOf<T>();
                byte *src = b + begin * UnsafeUtility.SizeOf<T>();
                UnsafeUtility.MemMove(dest, src, bytesToCopy);
            }
        }

        /// <summary>
        /// Shifts elements toward the end of this list, increasing its length.
        /// </summary>
        /// <remarks>
        /// Right-shifts elements in the list so as to create 'free' slots at the beginning or in the middle.
        ///
        /// The length is increased by `count`. If necessary, the capacity will be increased accordingly.
        ///
        /// If `count` equals `0`, the method does nothing.
        ///
        /// The element at index `index` will be copied to index `index + count`, the element at index `index + 1` will be copied to `index + count + 1`, and so forth.
        ///
        /// The indexes `index` up to `index + count` are not cleared: they will contain whatever values they held prior.
        /// </remarks>
        /// <param name="index">The index of the first element that will be shifted up.</param>
        /// <param name="count">The number of elements to insert.</param>
        /// <exception cref="ArgumentException">Thrown if `count` is negative.</exception>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if `index` is out of bounds.</exception>
        public void InsertRange(int index, int count) => InsertRangeWithBeginEnd(index, index + count);

        /// <summary>
        /// Inserts a single element at an index. Increments the length by 1.
        /// </summary>
        /// <param name="index">The index at which to insert the element.</param>
        /// <param name="item">The element to insert.</param>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if the index is out of bounds.</exception>
        public void Insert(int index, in T item)
        {
            InsertRangeWithBeginEnd(index, index+1);
            this[index] = item;
        }

        /// <summary>
        /// Copies the last element of this list to an index. Decrements the length by 1.
        /// </summary>
        /// <remarks>Useful as a cheap way to remove elements from a list when you don't care about preserving order.</remarks>
        /// <param name="index">The index to overwrite with the last element.</param>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if the index is out of bounds.</exception>
        public void RemoveAtSwapBack(int index)
        {
            RemoveRangeSwapBack(index, 1);
        }

        /// <summary>
        /// Copies the last *N* elements of this list to a range in this list. Decrements the length by *N*.
        /// </summary>
        /// <remarks>
        /// Copies the last `count`-numbered elements to the range starting at `index`.
        ///
        /// Useful as a cheap way to remove elements from a list when you don't care about preserving order.
        ///
        /// Does nothing if the count is less than 1.
        /// </remarks>
        /// <param name="index">The first index of the destination range.</param>
        /// <param name="count">The number of elements to copy and the amount by which to decrement the length.</param>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if the index is out of bounds.</exception>
        public void RemoveRangeSwapBack(int index, int count)
        {
            if (count > 0)
            {
                int copyFrom = math.max(Length - count, index + count);

                unsafe
                {
                    var sizeOf = UnsafeUtility.SizeOf<T>();
                    void* dst = Buffer + index * sizeOf;
                    void* src = Buffer + copyFrom * sizeOf;
                    UnsafeUtility.MemCpy(dst, src, (Length - copyFrom) * sizeOf);
                }

                Length -= count;
            }
        }

        /// <summary>
        /// Removes the element at an index. Shifts everything above the index down by one and decrements the length by 1.
        /// </summary>
        /// <param name="index">The index of the element to remove.</param>
        /// <remarks>
        /// If you don't care about preserving the order of the elements, `RemoveAtSwapBack` is a more efficient way to remove an element.
        /// </remarks>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if the index is out of bounds.</exception>
        public void RemoveAt(int index)
        {
            RemoveRange(index, 1);
        }

        /// <summary>
        /// Removes *N* elements of a range. Shifts everything above the range down by *N* and decrements the length by *N*.
        /// </summary>
        /// <remarks>
        /// If you don't care about preserving the order of the elements, `RemoveAtSwapBack` is a more efficient way to remove elements.
        /// </remarks>
        /// <param name="index">The first index of the range to remove.</param>
        /// <param name="count">The number of elements to remove.</param>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if the index is out of bounds.</exception>
        public void RemoveRange(int index, int count)
        {
            if (count > 0)
            {
                int copyFrom = math.min(index + count, Length);

                unsafe
                {
                    var sizeOf = UnsafeUtility.SizeOf<T>();
                    void* dst = Buffer + index * sizeOf;
                    void* src = Buffer + copyFrom * sizeOf;
                    UnsafeUtility.MemCpy(dst, src, (Length - copyFrom) * sizeOf);
                }

                Length -= count;
            }
        }

        /// <summary>
        /// Returns a managed array that is a copy of this list.
        /// </summary>
        /// <returns>A managed array that is a copy of this list.</returns>
        [ExcludeFromBurstCompatTesting("Returns managed array")]
        public T[] ToArray()
        {
            var result = new T[Length];
            unsafe
            {
                byte* s = Buffer;
                fixed(T* d = result)
                    UnsafeUtility.MemCpy(d, s, LengthInBytes);
            }
            return result;
        }

        /// <summary>
        /// Returns an array that is a copy of this list.
        /// </summary>
        /// <param name="allocator">The allocator to use.</param>
        /// <returns>An array that is a copy of this list.</returns>
        public NativeArray<T> ToNativeArray(AllocatorManager.AllocatorHandle allocator)
        {
            unsafe
            {
                var copy = CollectionHelper.CreateNativeArray<T>(Length, allocator, NativeArrayOptions.UninitializedMemory);
                UnsafeUtility.MemCpy(copy.GetUnsafePtr(), Buffer, LengthInBytes);
                return copy;
            }
        }
    }

    [GenerateTestsForBurstCompatibility]
    struct FixedList
    {
        [GenerateTestsForBurstCompatibility(GenericTypeArguments = new [] { typeof(int) })]
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        internal static int PaddingBytes<T>() where T : unmanaged
        {
            return math.max(0, math.min(6, (1 << math.tzcnt(UnsafeUtility.SizeOf<T>())) - 2));
        }

        [GenerateTestsForBurstCompatibility(GenericTypeArguments = new [] { typeof(int), typeof(int) })]
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        internal static int StorageBytes<BUFFER,T>() where BUFFER : unmanaged where T : unmanaged
        {
            return UnsafeUtility.SizeOf<BUFFER>() - UnsafeUtility.SizeOf<ushort>() - PaddingBytes<T>();
        }

        [GenerateTestsForBurstCompatibility(GenericTypeArguments = new [] { typeof(int), typeof(int) })]
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        internal static int Capacity<BUFFER,T>() where BUFFER : unmanaged where T : unmanaged
        {
            return StorageBytes<BUFFER,T>() / UnsafeUtility.SizeOf<T>();
        }

        [GenerateTestsForBurstCompatibility(GenericTypeArguments = new [] { typeof(int), typeof(int) })]
        [Conditional("ENABLE_UNITY_COLLECTIONS_CHECKS"), Conditional("UNITY_DOTS_DEBUG")]
        internal static void CheckResize<BUFFER,T>(int newLength) where BUFFER : unmanaged where T : unmanaged
        {
            var Capacity = Capacity<BUFFER,T>();
            if (newLength < 0 || newLength > Capacity)
                throw new IndexOutOfRangeException($"NewLength {newLength} is out of range of '{Capacity}' Capacity.");
        }
    }

<#
var SIZES = new int[]{32,64,128,512,4096};
for(var size = 0; size < 5; ++size)
{
    var BYTES = SIZES[size];
    var BUFFER_BYTES = BYTES;
    var TYPENAME = String.Format("FixedList{0}Bytes", BYTES);
    var OLD_TYPENAME = String.Format("FixedList{0}", BYTES);

#>
    /// <summary>
    /// An unmanaged, resizable list whose content is all stored directly in the <#=BYTES#>-byte struct. Useful for small lists.
    /// </summary>
    /// <typeparam name="T">The type of the elements.</typeparam>
    [Serializable]
    [DebuggerTypeProxy(typeof(<#=TYPENAME#>DebugView<>))]
    [GenerateTestsForBurstCompatibility(GenericTypeArguments = new [] { typeof(int) })]
    public struct <#=TYPENAME#><T>
    : INativeList<T>
    , IEnumerable<T> // Used by collection initializers.
<#
    foreach(var OTHERBYTES in SIZES)
    {
        var OTHERTYPENAME = String.Format("FixedList{0}Bytes", OTHERBYTES);
        WriteLine("    , IEquatable<{0}<T>>", OTHERTYPENAME);
        WriteLine("    , IComparable<{0}<T>>", OTHERTYPENAME);
    }
#>    where T : unmanaged
    {
        [SerializeField] internal FixedBytes<#=BUFFER_BYTES#>Align8 data;

        internal ushort length
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            readonly get
            {
                unsafe
                {
                    fixed(void* ptr = &data)
                        return *((ushort*)ptr);
                }
            }

            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            set
            {
                unsafe
                {
                    fixed (void* ptr = &data)
                        *((ushort*)ptr) = value;
                }
            }
        }

        internal readonly unsafe byte* buffer
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            get
            {
                unsafe
                {
                    fixed (void* ptr = &data)
                        return ((byte*)ptr) + UnsafeUtility.SizeOf<ushort>();
                }
            }
        }

        /// <summary>
        /// The current number of items in this list.
        /// </summary>
        /// <value>The current number of items in this list.</value>
        [CreateProperty]
        public int Length
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            readonly get => length;
            set
            {
                FixedList.CheckResize<FixedBytes<#=BUFFER_BYTES#>Align8,T>(value);
                length = (ushort)value;
            }
        }

        /// <summary>
        /// A property in order to display items in the Entity Inspector.
        /// </summary>
        [CreateProperty] IEnumerable<T> Elements => this.ToArray();

        /// <summary>
        /// Whether this list is empty.
        /// </summary>
        /// <value>True if this string has no characters or if the container has not been constructed.</value>
        public readonly bool IsEmpty
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            get => Length == 0;
        }

        internal int LengthInBytes => Length * UnsafeUtility.SizeOf<T>();

        /// <summary>
        /// Returns a pointer to the first element of the list buffer.
        /// </summary>
        /// <remarks>
        /// The pointer returned by this method points into the internals of the target list object. It is the
        /// caller's responsibility to ensure that the pointer is not used after the list is destroyed or goes
        /// out of scope.
        /// </remarks>
        /// <returns>A pointer to the first element of the list buffer.</returns>
        internal readonly unsafe byte* Buffer
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            get
            {
                return buffer + FixedList.PaddingBytes<T>();
            }
        }

        /// <summary>
        /// The number of elements that can fit in this list.
        /// </summary>
        /// <value>The number of elements that can fit in this list.</value>
        /// <remarks>The capacity of a FixedList cannot be changed. The setter is included only for conformity with <see cref="INativeList{T}"/>.</remarks>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if the new value does not match the current capacity.</exception>
        public int Capacity
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            readonly get
            {
                return FixedList.Capacity<FixedBytes<#=BUFFER_BYTES#>Align8,T>();
            }

            set
            {
                CollectionHelper.CheckCapacityInRange(value, Length);
            }
        }

        /// <summary>
        /// The element at a given index.
        /// </summary>
        /// <param name="index">An index.</param>
        /// <value>The value to store at the index.</value>
        /// <exception cref="IndexOutOfRangeException">Thrown if the index is out of bounds.</exception>
        public T this[int index]
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            readonly get
            {
                CollectionHelper.CheckIndexInRange(index, length);
                unsafe
                {
                    return UnsafeUtility.ReadArrayElement<T>(Buffer, CollectionHelper.AssumePositive(index));
                }
            }

            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            set
            {
                CollectionHelper.CheckIndexInRange(index, length);
                unsafe
                {
                    UnsafeUtility.WriteArrayElement<T>(Buffer, CollectionHelper.AssumePositive(index), value);
                }
            }
        }

        /// <summary>
        /// Returns the element at a given index.
        /// </summary>
        /// <param name="index">An index.</param>
        /// <returns>The list element at the index.</returns>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public ref T ElementAt(int index)
        {
            CollectionHelper.CheckIndexInRange(index, length);
            unsafe
            {
                return ref UnsafeUtility.ArrayElementAsRef<T>(Buffer, index);
            }
        }

        /// <summary>
        /// Returns the hash code of this list.
        /// </summary>
        /// <remarks>
        /// Only the content of the list (the bytes of the elements) are included in the hash. Any bytes beyond the length are not part of the hash.</remarks>
        /// <returns>The hash code of this list.</returns>
        public override int GetHashCode()
        {
            unsafe
            {
                return (int)CollectionHelper.Hash(Buffer, LengthInBytes);
            }
        }

        /// <summary>
        /// Appends an element to the end of this list. Increments the length by 1.
        /// </summary>
        /// <remarks>
        /// The same as <see cref="AddNoResize"/>. Included only for consistency with the other list types.
        /// If the element exceeds the capacity, throws cref="IndexOutOfRangeException", and the list is unchanged.
        /// </remarks>
        /// <param name="item">The element to append at the end of the list.</param>
        /// <exception cref="IndexOutOfRangeException">Thrown if the append exceeds the capacity.</exception>
        public void Add(in T item) => AddNoResize(in item);

        /// <summary>
        /// Appends elements from a buffer to the end of this list. Increments the length by the number of appended elements.
        /// </summary>
        /// <remarks>
        /// The same as <see cref="AddRangeNoResize"/>. Included only for consistency with the other list types.
        /// If the elements exceeds the capacity, throws cref="IndexOutOfRangeException", and the list is unchanged.
        /// </remarks>
        /// <param name="ptr">A buffer.</param>
        /// <param name="length">The number of elements from the buffer to append.</param>
        /// <exception cref="IndexOutOfRangeException">Thrown if the append exceeds the capacity.</exception>
        public unsafe void AddRange(void* ptr, int length) => AddRangeNoResize(ptr, length);

        /// <summary>
        /// Appends an element to the end of this list. Increments the length by 1.
        /// </summary>
        /// <remarks>
        /// If the element exceeds the capacity, throws cref="IndexOutOfRangeException", and the list is unchanged.
        /// </remarks>
        /// <param name="item">The element to append at the end of the list.</param>
        /// <exception cref="IndexOutOfRangeException">Thrown if the append exceeds the capacity.</exception>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void AddNoResize(in T item)
        {
            this[Length++] = item;
        }

        /// <summary>
        /// Appends elements from a buffer to the end of this list. Increments the length by the number of appended elements.
        /// </summary>
        /// <remarks>
        /// If the elements exceeds the capacity, throws cref="IndexOutOfRangeException", and the list is unchanged.
        /// </remarks>
        /// <param name="ptr">A buffer.</param>
        /// <param name="length">The number of elements from the buffer to append.</param>
        /// <exception cref="IndexOutOfRangeException">Thrown if the append exceeds the capacity.</exception>
        public unsafe void AddRangeNoResize(void* ptr, int length)
        {
            var idx = Length;
            Length += length;
            UnsafeUtility.MemCpy((T*)Buffer + idx, ptr, UnsafeUtility.SizeOf<T>() * length);
        }

        /// <summary>
        /// Appends value count times to the end of this list.
        /// </summary>
        /// <param name="value">The value to add to the end of this list.</param>
        /// <param name="count">The number of times to replicate the value.</param>
        /// <exception cref="IndexOutOfRangeException">Thrown if the append exceeds the capacity.</exception>
        public unsafe void AddReplicate(in T value, int count)
        {
            var idx = Length;
            Length += count;
            fixed (T* ptr = &value)
                UnsafeUtility.MemCpyReplicate((T*)Buffer + idx, ptr, UnsafeUtility.SizeOf<T>(), count);
        }

        /// <summary>
        /// Sets the length to 0.
        /// </summary>
        /// <remarks> Does *not* zero out the bytes.</remarks>
        public void Clear()
        {
            Length = 0;
        }

        /// <summary>
        /// Shifts elements toward the end of this list, increasing its length.
        /// </summary>
        /// <remarks>
        /// Right-shifts elements in the list so as to create 'free' slots at the beginning or in the middle.
        ///
        /// The length is increased by `end - begin`.
        ///
        /// If `end` equals `begin`, the method does nothing.
        ///
        /// The element at index `begin` will be copied to index `end`, the element at index `begin + 1` will be copied to `end + 1`, and so forth.
        ///
        /// The indexes `begin` up to `end` are not cleared: they will contain whatever values they held prior.
        /// </remarks>
        /// <param name="begin">The index of the first element that will be shifted up.</param>
        /// <param name="end">The index where the first shifted element will end up.</param>
        /// <exception cref="IndexOutOfRangeException">Thrown if the new length exceeds the capacity.</exception>
        public void InsertRangeWithBeginEnd(int begin, int end)
        {
            int items = end - begin;
            if(items < 1)
                return;
            int itemsToCopy = length - begin;
            Length += items;
            if(itemsToCopy < 1)
                return;
            int bytesToCopy = itemsToCopy * UnsafeUtility.SizeOf<T>();
            unsafe
            {
                byte *b = Buffer;
                byte *dest = b + end * UnsafeUtility.SizeOf<T>();
                byte *src = b + begin * UnsafeUtility.SizeOf<T>();
                UnsafeUtility.MemMove(dest, src, bytesToCopy);
            }
        }

        /// <summary>
        /// Shifts elements toward the end of this list, increasing its length.
        /// </summary>
        /// <remarks>
        /// Right-shifts elements in the list so as to create 'free' slots at the beginning or in the middle.
        ///
        /// The length is increased by `count`. If necessary, the capacity will be increased accordingly.
        ///
        /// If `count` equals `0`, the method does nothing.
        ///
        /// The element at index `index` will be copied to index `index + count`, the element at index `index + 1` will be copied to `index + count + 1`, and so forth.
        ///
        /// The indexes `index` up to `index + count` are not cleared: they will contain whatever values they held prior.
        /// </remarks>
        /// <param name="index">The index of the first element that will be shifted up.</param>
        /// <param name="count">The number of elements to insert.</param>
        /// <exception cref="ArgumentException">Thrown if `count` is negative.</exception>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if `index` is out of bounds.</exception>
        public void InsertRange(int index, int count) => InsertRangeWithBeginEnd(index, index + count);

        /// <summary>
        /// Inserts a single element at an index. Increments the length by 1.
        /// </summary>
        /// <param name="index">The index at which to insert the element.</param>
        /// <param name="item">The element to insert.</param>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if the index is out of bounds.</exception>
        public void Insert(int index, in T item)
        {
            InsertRangeWithBeginEnd(index, index+1);
            this[index] = item;
        }

        /// <summary>
        /// Copies the last element of this list to an index. Decrements the length by 1.
        /// </summary>
        /// <remarks>Useful as a cheap way to remove elements from a list when you don't care about preserving order.</remarks>
        /// <param name="index">The index to overwrite with the last element.</param>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if the index is out of bounds.</exception>
        public void RemoveAtSwapBack(int index)
        {
            RemoveRangeSwapBack(index, 1);
        }

        /// <summary>
        /// Copies the last *N* elements of this list to a range in this list. Decrements the length by *N*.
        /// </summary>
        /// <remarks>
        /// Copies the last `count`-numbered elements to the range starting at `index`.
        ///
        /// Useful as a cheap way to remove elements from a list when you don't care about preserving order.
        ///
        /// Does nothing if the count is less than 1.
        /// </remarks>
        /// <param name="index">The first index of the destination range.</param>
        /// <param name="count">The number of elements to copy and the amount by which to decrement the length.</param>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if the index is out of bounds.</exception>
        public void RemoveRangeSwapBack(int index, int count)
        {
            if (count > 0)
            {
                int copyFrom = math.max(Length - count, index + count);

                unsafe
                {
                    var sizeOf = UnsafeUtility.SizeOf<T>();
                    void* dst = Buffer + index * sizeOf;
                    void* src = Buffer + copyFrom * sizeOf;
                    UnsafeUtility.MemCpy(dst, src, (Length - copyFrom) * sizeOf);
                }

                Length -= count;
            }
        }

        /// <summary>
        /// Removes the element at an index. Shifts everything above the index down by one and decrements the length by 1.
        /// </summary>
        /// <param name="index">The index of the element to remove.</param>
        /// <remarks>
        /// If you don't care about preserving the order of the elements, `RemoveAtSwapBack` is a more efficient way to remove an element.
        /// </remarks>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if the index is out of bounds.</exception>
        public void RemoveAt(int index)
        {
            RemoveRange(index, 1);
        }

        /// <summary>
        /// Removes *N* elements of a range. Shifts everything above the range down by *N* and decrements the length by *N*.
        /// </summary>
        /// <remarks>
        /// If you don't care about preserving the order of the elements, `RemoveAtSwapBack` is a more efficient way to remove elements.
        /// </remarks>
        /// <param name="index">The first index of the range to remove.</param>
        /// <param name="count">The number of elements to remove.</param>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if the index is out of bounds.</exception>
        public void RemoveRange(int index, int count)
        {
            if (count > 0)
            {
                int copyFrom = math.min(index + count, Length);

                unsafe
                {
                    var sizeOf = UnsafeUtility.SizeOf<T>();
                    void* dst = Buffer + index * sizeOf;
                    void* src = Buffer + copyFrom * sizeOf;
                    UnsafeUtility.MemCpy(dst, src, (Length - copyFrom) * sizeOf);
                }

                Length -= count;
            }
        }

        /// <summary>
        /// Returns a managed array that is a copy of this list.
        /// </summary>
        /// <returns>A managed array that is a copy of this list.</returns>
        [ExcludeFromBurstCompatTesting("Returns managed array")]
        public T[] ToArray()
        {
            var result = new T[Length];
            unsafe
            {
                byte* s = Buffer;
                fixed(T* d = result)
                    UnsafeUtility.MemCpy(d, s, LengthInBytes);
            }
            return result;
        }

        /// <summary>
        /// Returns an array that is a copy of this list.
        /// </summary>
        /// <param name="allocator">The allocator to use.</param>
        /// <returns>An array that is a copy of this list.</returns>
        public NativeArray<T> ToNativeArray(AllocatorManager.AllocatorHandle allocator)
        {
            unsafe
            {
                var copy = CollectionHelper.CreateNativeArray<T>(Length, allocator, NativeArrayOptions.UninitializedMemory);
                UnsafeUtility.MemCpy(copy.GetUnsafePtr(), Buffer, LengthInBytes);
                return copy;
            }
        }

<#
    foreach(var OTHERBYTES in SIZES)
    {
        var OTHER_BUFFER_BYTES = OTHERBYTES;
        var OTHERTYPENAME = String.Format("FixedList{0}Bytes", OTHERBYTES);
#>

        /// <summary>
        /// Returns true if two lists are equal.
        /// </summary>
        /// <remarks>Two lists are equal if their length and bytes are equal.</remarks>
        /// <param name="a">The first list to compare for equality.</param>
        /// <param name="b">The second list to compare for equality.</param>
        /// <returns>True if the two lists are equal.</returns>
        public static bool operator ==(in <#=TYPENAME#><T> a, in <#=OTHERTYPENAME#><T> b)
        {
            unsafe
            {
                if(a.length != b.length)
                    return false;
                return UnsafeUtility.MemCmp(a.Buffer, b.Buffer, a.LengthInBytes) == 0;
            }
        }

        /// <summary>
        /// Returns true if two lists are unequal.
        /// </summary>
        /// <remarks>Two lists are equal if their length and bytes are equal.</remarks>
        /// <param name="a">The first list to compare for inequality.</param>
        /// <param name="b">The second list to compare for inequality.</param>
        /// <returns>True if the two lists are unequal.</returns>
        public static bool operator !=(in <#=TYPENAME#><T> a, in <#=OTHERTYPENAME#><T> b)
        {
            return !(a == b);
        }

        /// <summary>
        /// Returns a number denoting whether this list should be placed before or after another list in a sort.
        /// </summary>
        /// <param name="other">A list to to compare with.</param>
        /// <returns>An integer denoting the respective sort position of the list relative to the other:
        ///
        /// 0 denotes that both lists should have the same position in a sort.
        /// -1 denotes that this list should precede the other list in a sort.
        /// +1 denotes that this list should follow the other list in a sort.
        /// </returns>
        public int CompareTo(<#=OTHERTYPENAME#><T> other)
        {
            unsafe
            {
                byte* a = buffer;
                byte* b = other.buffer;
                var aa = a + FixedList.PaddingBytes<T>();
                var bb = b + FixedList.PaddingBytes<T>();
                var mini = math.min(Length, other.Length);
                for(var i = 0; i < mini; ++i)
                {
                    var j = UnsafeUtility.MemCmp(aa + sizeof(T) * i, bb + sizeof(T) * i, sizeof(T));
                    if(j != 0)
                        return j;
                }
                return Length.CompareTo(other.Length);
            }
        }

        /// <summary>
        /// Returns true if this list and another list are equal.
        /// </summary>
        /// <remarks>Two lists are equal if their length and bytes are equal.</remarks>
        /// <param name="other">The list to compare for equality.</param>
        /// <returns>True if the two lists are equal.</returns>
        public bool Equals(<#=OTHERTYPENAME#><T> other)
        {
            return CompareTo(other) == 0;
        }

<#
        if(BYTES != OTHERBYTES)
        {
#>

        /// <summary>
        /// Initializes and returns an instance of <#=TYPENAME#> with content copied from another list.
        /// </summary>
        /// <param name="other">The list to copy.</param>
        /// <exception cref="IndexOutOfRangeException">Throws if the other list's length exceeds the capacity of <#=TYPENAME#>&lt;T&gt;.</exception>
        public <#=TYPENAME#>(in <#=OTHERTYPENAME#><T> other)
        {
            this = default;
            var error = Initialize(other);
            if(error != 0)
                FixedList.CheckResize<FixedBytes<#=BUFFER_BYTES#>Align8,T>(other.Length);
        }

        /// <summary>
        /// Initializes an instance of <#=TYPENAME#> with content copied from another list.
        /// </summary>
        /// <param name="other">The list to copy.</param>
        /// <returns>zero on success, or non-zero on error.</returns>
        internal int Initialize(in <#=OTHERTYPENAME#><T> other)
        {
            if(other.Length > Capacity)
                return (int)CopyError.Truncation;
            length = other.length;
            unsafe
            {
                UnsafeUtility.MemCpy(Buffer, other.Buffer, LengthInBytes);
            }
            return 0;
        }

        /// <summary>
        /// Returns a new list that is a copy of another list.
        /// </summary>
        /// <param name="other">The list to copy.</param>
        /// <returns>A new list that is a copy of the other.</returns>
        /// <exception cref="IndexOutOfRangeException">Throws if the other list's length exceeds the capacity of <#=TYPENAME#>&lt;T&gt;.</exception>
        public static implicit operator <#=TYPENAME#><T>(in <#=OTHERTYPENAME#><T> other)
        {
            return new <#=TYPENAME#><T>(other);
        }
<#
        }
    }
#>

        /// <summary>
        /// Returns true if the list is equal to an object.
        /// </summary>
        /// <remarks>Two lists are equal if their length and bytes are equal.
        ///
        /// A FixedList*N*&lt;T&gt; can only be equal to another FixedList*N*&lt;T&gt; with the same *N* and T.
        /// </remarks>
        /// <param name="obj">An object to compare for equality.</param>
        /// <returns>True if the list is equal to the object.</returns>
        [ExcludeFromBurstCompatTesting("Takes managed object")]
        public override bool Equals(object obj)
        {
<#
    foreach(var OTHERBYTES in SIZES)
    {
        var OTHERTYPENAME = String.Format("FixedList{0}Bytes", OTHERBYTES);
        WriteLine("            if(obj is {0}<T> a{0}) return Equals(a{0});", OTHERTYPENAME);
    }
#>
            return false;
        }

        /// <summary>
        /// An enumerator over the elements of a <#=TYPENAME#>&lt;T&gt;.
        /// </summary>
        /// <remarks>
        /// In an enumerator's initial state, `Current` cannot be read. The first <see cref="MoveNext"/> call advances the enumerator to the first element.
        /// </remarks>
        public struct Enumerator : IEnumerator<T>
        {
            <#=TYPENAME#><T> m_List;
            int m_Index;

            /// <summary>
            /// Initializes and returns an instance of <#=TYPENAME#>&lt;T&gt;.
            /// </summary>
            /// <param name="list">The list for which to create an enumerator.</param>
            public Enumerator(ref <#=TYPENAME#><T> list)
            {
                m_List = list;
                m_Index = -1;
            }

            /// <summary>
            /// Does nothing.
            /// </summary>
            public void Dispose()
            {
            }

            /// <summary>
            /// Advances the enumerator to the next element.
            /// </summary>
            /// <returns>True if <see cref="Current"/> is valid to read after the call.</returns>
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            public bool MoveNext()
            {
                m_Index++;
                return m_Index < m_List.Length;
            }

            /// <summary>
            /// Resets the enumerator to its initial state.
            /// </summary>
            public void Reset()
            {
                m_Index = -1;
            }

            /// <summary>
            /// The current element.
            /// </summary>
            /// <value>The current element.</value>
            public T Current
            {
                [MethodImpl(MethodImplOptions.AggressiveInlining)]
                get => m_List[m_Index]; // Let <#=TYPENAME#><T> indexer check for out of range.
            }

            object IEnumerator.Current => Current;
        }

        /// <summary>
        /// Returns an enumerator for iterating over the elements of this list.
        /// </summary>
        /// <returns>An enumerator for iterating over the elements of this list.</returns>
        public Enumerator GetEnumerator()
        {
            return new Enumerator(ref this);
        }

        /// <summary>
        /// This method is not implemented. Use <see cref="GetEnumerator"/> instead.
        /// </summary>
        /// <returns>Nothing because it always throws <see cref="NotImplementedException"/>.</returns>
        /// <exception cref="NotImplementedException">Method is not implemented.</exception>
        IEnumerator IEnumerable.GetEnumerator()
        {
            throw new NotImplementedException();
        }

        /// <summary>
        /// This method is not implemented. Use <see cref="GetEnumerator"/> instead.
        /// </summary>
        /// <returns>Nothing because it always throws <see cref="NotImplementedException"/>.</returns>
        /// <exception cref="NotImplementedException">Method is not implemented.</exception>
        IEnumerator<T> IEnumerable<T>.GetEnumerator()
        {
            throw new NotImplementedException();
        }
    }

    /// <summary>
    /// Provides extension methods for <#=TYPENAME#>.
    /// </summary>
    [GenerateTestsForBurstCompatibility]
    public unsafe static class <#=TYPENAME#>Extensions
    {
        /// <summary>
        /// Finds the index of the first occurrence of a particular value in this list.
        /// </summary>
        /// <typeparam name="T">The type of elements in this list.</typeparam>
        /// <typeparam name="U">The value type.</typeparam>
        /// <param name="list">The list to search.</param>
        /// <param name="value">The value to locate.</param>
        /// <returns>The index of the first occurrence of the value. Returns -1 if no occurrence is found.</returns>
        [GenerateTestsForBurstCompatibility(GenericTypeArguments = new [] { typeof(int), typeof(int) })]
        public static int IndexOf<T, U>(this ref <#=TYPENAME#><T> list, U value) where T : unmanaged, IEquatable<U>
        {
            return NativeArrayExtensions.IndexOf<T, U>(list.Buffer, list.Length, value);
        }

        /// <summary>
        /// Returns true if a particular value is present in this list.
        /// </summary>
        /// <typeparam name="T">The type of elements in this list.</typeparam>
        /// <typeparam name="U">The value type.</typeparam>
        /// <param name="list">The list to search.</param>
        /// <param name="value">The value to locate.</param>
        /// <returns>True if the value is present in this list.</returns>
        [GenerateTestsForBurstCompatibility(GenericTypeArguments = new [] { typeof(int), typeof(int) })]
        public static bool Contains<T, U>(this ref <#=TYPENAME#><T> list, U value) where T : unmanaged, IEquatable<U>
        {
            return list.IndexOf(value) != -1;
        }

        /// <summary>
        /// Removes the first occurrence of a particular value in this list.
        /// </summary>
        /// <remarks>
        /// If a value is removed, all elements after it are shifted down by one, and the list's length is decremented by one.
        ///
        /// If you don't need to preserve the order of the remaining elements, <see cref="Unity.Collections.<#=TYPENAME#>Extensions.RemoveSwapBack{T, U}"/> is a cheaper alternative.
        /// </remarks>
        /// <typeparam name="T">The type of elements in this list.</typeparam>
        /// <typeparam name="U">The value type.</typeparam>
        /// <param name="list">The list to search.</param>
        /// <param name="value">The value to locate and remove.</param>
        /// <returns>True if the value was found and removed.</returns>
        [GenerateTestsForBurstCompatibility(GenericTypeArguments = new [] { typeof(int), typeof(int) })]
        public static bool Remove<T, U>(this ref <#=TYPENAME#><T> list, U value) where T : unmanaged, IEquatable<U>
        {
            int index = list.IndexOf(value);
            if (index < 0)
            {
                return false;
            }

            list.RemoveAt(index);

            return true;
        }

        /// <summary>
        /// Removes the first occurrence of a particular value in this list.
        /// </summary>
        /// <remarks>
        /// If a value is removed, the last element of the list is copied to overwrite the removed value, and the list's length is decremented by one.
        ///
        /// This is cheaper than <see cref="Remove"/>, but the order of the remaining elements is not preserved.
        /// </remarks>
        /// <typeparam name="T">The type of elements in this list.</typeparam>
        /// <typeparam name="U">The value type.</typeparam>
        /// <param name="list">The list to search.</param>
        /// <param name="value">The value to locate and remove.</param>
        /// <returns>Returns true if the item is removed.</returns>
        [GenerateTestsForBurstCompatibility(GenericTypeArguments = new [] { typeof(int), typeof(int) })]
        public static bool RemoveSwapBack<T, U>(this ref <#=TYPENAME#><T> list, U value) where T : unmanaged, IEquatable<U>
        {
            var index = list.IndexOf(value);
            if (index == -1)
            {
                return false;
            }

            list.RemoveAtSwapBack(index);

            return true;
        }
    }

    sealed class <#=TYPENAME#>DebugView<T> where T : unmanaged
    {
        <#=TYPENAME#><T> m_List;
        public <#=TYPENAME#>DebugView(<#=TYPENAME#><T> list)
        {
            m_List = list;
        }
        public T[] Items => m_List.ToArray();
    }
<#
}
#>

<#
var TYPES = new string[]{"byte","int","float"};
var TYPESIZES = new int[]{1,4,4};
for(var type = 0; type < 3; ++type)
for(var size = 0; size < 5; ++size)
{
    var BYTES = SIZES[size];
    var TYPE = TYPES[type];
    var TYPESIZE = TYPESIZES[type];
    var BUFFER_BYTES = BYTES;
    var TYPENAME = String.Format("FixedList{0}{1}", new CultureInfo("en-US").TextInfo.ToTitleCase(TYPE), BYTES);
    var NEW_TYPENAME = $"FixedList{BYTES}Bytes<{TYPE}>";
#>


<#
}
#>
    /// <summary>
    /// Provides extension methods for FixedList*N*.
    /// </summary>
    public static class FixedListExtensions
    {
<#
for(var size = 0; size < 5; ++size)
{
    var BYTES = SIZES[size];
    var BUFFER_BYTES = BYTES;
    var TYPENAME = String.Format("FixedList{0}Bytes", BYTES);
#>

        /// <summary>
        /// Sorts the elements in this list in ascending order.
        /// </summary>
        /// <typeparam name="T">The type of the elements.</typeparam>
        /// <param name="list">The list to sort.</param>
        [GenerateTestsForBurstCompatibility(GenericTypeArguments = new [] { typeof(int) })]
        public static void Sort<T>(this ref <#=TYPENAME#><T> list)
        where T : unmanaged, IComparable<T>
        {
            unsafe
            {
                var c = list.buffer + FixedList.PaddingBytes<T>();
                NativeSortExtension.Sort((T*)c, list.Length);
            }
        }

        /// <summary>
        /// Sorts the elements in this list using a custom comparison.
        /// </summary>
        /// <typeparam name="T">The type of the elements.</typeparam>
        /// <typeparam name="U">The type of the comparer.</typeparam>
        /// <param name="list">The list to sort.</param>
        /// <param name="comp">The comparison function used to determine the relative order of the elements.</param>
        [GenerateTestsForBurstCompatibility(GenericTypeArguments = new [] { typeof(int), typeof(NativeSortExtension.DefaultComparer<int>) })]
        public static void Sort<T, U>(this ref <#=TYPENAME#><T> list, U comp)
        where T : unmanaged, IComparable<T>
        where U : IComparer<T>
        {
            unsafe
            {
                var c = list.buffer + FixedList.PaddingBytes<T>();
                NativeSortExtension.Sort((T*)c, list.Length, comp);
            }
        }

<#
}
#>
    }
}