Cilador.Clone.CloningExtensions.TryGetVariableIndex C# (CSharp) Метод

        public static bool TryGetVariableIndex(this Instruction instruction, out int? variableIndex)
        {
            Contract.Requires(instruction != null);
            Contract.Ensures(Contract.ValueAtReturn<int?>(out variableIndex).HasValue || !Contract.Result<bool>());

            switch (instruction.OpCode.Code)
            {
                case Code.Ldloc_0:
                case Code.Stloc_0:
                    variableIndex = 0;
                    return true;

                case Code.Ldloc_1:
                case Code.Stloc_1:
                    variableIndex = 1;
                    return true;

                case Code.Ldloc_2:
                case Code.Stloc_2:
                    variableIndex = 2;
                    return true;

                case Code.Ldloc_3:
                case Code.Stloc_3:
                    variableIndex = 3;
                    return true;

                case Code.Ldloc:
                case Code.Ldloc_S:
                case Code.Ldloca:
                case Code.Ldloca_S:
                case Code.Stloc:
                case Code.Stloc_S:
                    variableIndex = ((VariableDefinition)instruction.Operand).Index;
                    if (variableIndex < 0)
                    {
                        throw new InvalidOperationException(
                            $"Did not expect a negative variable index for {((VariableDefinition)instruction.Operand).Name}");
                    }
                    return true;

                default:
                    variableIndex = default(int?);
                    return false;
            }
        }