add (untested) support for metadata v38

Il2CppInspector.Common/Next/Metadata/GenericContainerIndex.cs

@@ -0,0 +1,76 @@
+using VersionedSerialization;
+
+namespace Il2CppInspector.Next.Metadata;
+
+public struct GenericContainerIndex(int value) : IReadable, IEquatable<GenericContainerIndex>
+{
+    public const string TagPrefix = nameof(GenericContainerIndex); 
+
+    private int _value = value;
+
+    public static implicit operator int(GenericContainerIndex idx) => idx._value;
+    public static implicit operator GenericContainerIndex(int idx) => new(idx);
+
+    public static int Size(in StructVersion version = default, bool is32Bit = false)
+    {
+        if (version >= MetadataVersions.V380
+            && version.Tag != null
+            && version.Tag.Contains(TagPrefix)
+            && !version.Tag.Contains($"{TagPrefix}4"))
+        {
+            if (version.Tag.Contains($"{TagPrefix}2"))
+                return sizeof(ushort);
+
+            if (version.Tag.Contains($"{TagPrefix}1"))
+                return sizeof(byte);
+        }
+
+        return sizeof(int);
+    }
+
+    public void Read<TReader>(ref TReader reader, in StructVersion version = default) where TReader : IReader, allows ref struct
+    {
+        if (version >= MetadataVersions.V380
+            && version.Tag != null
+            && version.Tag.Contains(TagPrefix)
+            && !version.Tag.Contains($"{TagPrefix}4"))
+        {
+            if (version.Tag.Contains($"{TagPrefix}2"))
+            {
+                _value = reader.ReadPrimitive<short>();
+                _value = _value == ushort.MaxValue ? -1 : _value;
+                return;
+            }
+
+            if (version.Tag.Contains($"{TagPrefix}1"))
+            {
+                _value = reader.ReadPrimitive<byte>();
+                _value = _value == byte.MaxValue ? -1 : _value;
+                return;
+            }
+        }
+
+        _value = reader.ReadPrimitive<int>();
+    }
+
+    #region Equality operators + ToString
+
+    public static bool operator ==(GenericContainerIndex left, GenericContainerIndex right)
+        => left._value == right._value;
+
+    public static bool operator !=(GenericContainerIndex left, GenericContainerIndex right)
+        => !(left == right);
+
+    public readonly override bool Equals(object? obj)
+        => obj is GenericContainerIndex other && Equals(other);
+
+    public readonly bool Equals(GenericContainerIndex other)
+        => this == other;
+
+    public readonly override int GetHashCode()
+        => HashCode.Combine(_value);
+
+    public readonly override string ToString() => _value.ToString();
+
+    #endregion
+}