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NitroxPatcher/PatternMatching/OpCodePattern.cs

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+using System;
+using System.Reflection.Emit;
+
+namespace NitroxPatcher.PatternMatching;
+
+public readonly struct OpCodePattern
+{
+    public bool Equals(OpCodePattern other) => Nullable.Equals(OpCode, other.OpCode);
+
+    public override bool Equals(object obj) => obj is OpCodePattern other && Equals(other);
+
+    public override int GetHashCode() => OpCode.GetHashCode();
+
+    public OpCode? OpCode { get; init; }
+
+    /// <summary>
+    ///     If true, similar opcodes will be matched as being the same.
+    /// </summary>
+    /// <remarks>
+    ///     Example for similar opcodes (call): call, callvirt and calli.
+    /// </remarks>
+    public bool WeakMatch { get; init; }
+
+    public bool IsAnyCall => WeakMatch && (OpCode == OpCodes.Call || OpCode == OpCodes.Callvirt || OpCode == OpCodes.Calli);
+
+    public static implicit operator OpCodePattern(OpCode opCode) => new() { OpCode = opCode };
+
+    public static bool operator ==(OpCodePattern pattern, OpCode opCode) => pattern.OpCode == opCode ||
+                                                                            (pattern.IsAnyCall && (opCode == OpCodes.Call || opCode == OpCodes.Callvirt || opCode == OpCodes.Calli));
+    public static bool operator ==(OpCode opCode, OpCodePattern pattern) => pattern == opCode;
+
+    public static bool operator !=(OpCodePattern pattern, OpCode opCode) => !(pattern == opCode);
+    public static bool operator !=(OpCode opCode, OpCodePattern pattern) => !(opCode == pattern);
+}