Fix source only package issue in nuget

Misaki.HighPerformance.LowLevel/contentFiles/cs/any/Buffer/IAllocator.cs

@@ -0,0 +1,111 @@
+using System.Diagnostics.CodeAnalysis;
+
+namespace Misaki.HighPerformance.LowLevel.Buffer;
+
+public readonly struct MemoryHandle : IEquatable<MemoryHandle>
+{
+    public readonly int id;
+    public readonly int generation;
+
+    public readonly static MemoryHandle Invalid = new(-1, -1);
+
+    public MemoryHandle(int id, int generation)
+    {
+        this.id = id;
+        this.generation = generation;
+    }
+
+    public bool Equals(MemoryHandle other)
+    {
+        return id == other.id && generation == other.generation;
+    }
+
+    public override bool Equals([NotNullWhen(true)] object? obj)
+    {
+        return obj is MemoryHandle other && Equals(other);
+    }
+
+    public override int GetHashCode()
+    {
+        return id ^ generation;
+    }
+
+    public override string? ToString()
+    {
+        return $"MemoryHandle(Id: {id}, Generation: {generation})";
+    }
+
+    public static bool operator ==(MemoryHandle left, MemoryHandle right)
+    {
+        return left.Equals(right);
+    }
+
+    public static bool operator !=(MemoryHandle left, MemoryHandle right)
+    {
+        return !(left == right);
+    }
+}
+
+/// <summary>
+/// A structure that encapsulates function pointers for memory allocation operations.
+/// </summary>
+public readonly unsafe struct AllocationHandle
+{
+    /// <summary>
+    /// Gets a pointer to the state instance associated with this allocation handle.
+    /// </summary>
+    public void* State
+    {
+        get; init;
+    }
+
+    /// <summary>
+    /// Gets a function pointer for allocating memory.
+    /// </summary>
+    public AllocFunc Alloc
+    {
+        get; init;
+    }
+
+    /// <summary>
+    /// Gets a function pointer for reallocating memory.
+    /// </summary>
+    public ReallocFunc Realloc
+    {
+        get; init;
+    }
+
+    /// <summary>
+    /// Gets a function pointer for freeing allocated memory.
+    /// </summary>
+    public FreeFunc Free
+    {
+        get; init;
+    }
+
+    /// <summary>
+    /// Gets a function pointer for validating a memory handle.
+    /// </summary>
+    public IsValidFunc IsValid
+    {
+        get; init;
+    }
+}
+
+/// <summary>
+/// Represents an state interface for managing memory allocations.
+/// </summary>
+/// <remarks>
+/// The state must be pined to a specific memory region.
+/// Otherwise the reference of the <see cref="AllocationHandle.State"/>, may become invalid and lead to undefined behavior.
+/// </remarks>
+public interface IAllocator
+{
+    /// <summary>
+    /// Gets a reference to the allocation handle associated with this state.
+    /// </summary>
+    AllocationHandle Handle
+    {
+        get;
+    }
+}