C# TypeInferenceContext.ExactInference方法代码示例

		//
		// Infers type arguments based on explicit arguments
		//
		public bool ExplicitTypeInference (ResolveContext ec, TypeInferenceContext type_inference, TypeSpec delegate_type)
		{
			if (!HasExplicitParameters)
				return false;

			if (!delegate_type.IsDelegate) {
				if (!delegate_type.IsExpressionTreeType)
					return false;

				delegate_type = TypeManager.GetTypeArguments (delegate_type) [0];
				if (!delegate_type.IsDelegate)
					return false;
			}
			
			AParametersCollection d_params = Delegate.GetParameters (delegate_type);
			if (d_params.Count != Parameters.Count)
				return false;

			var ptypes = Parameters.Types;
			var dtypes = d_params.Types;
			for (int i = 0; i < Parameters.Count; ++i) {
				if (type_inference.ExactInference (ptypes[i], dtypes[i]) == 0) {
					//
					// Continue when 0 (quick path) does not mean inference failure. Checking for
					// same type handles cases like int -> int
					//
					if (ptypes[i] == dtypes[i])
						continue;

					return false;
				}
			}

			return true;
		}

		//
		// Implements method type arguments inference
		//
		bool InferInPhases (ResolveContext ec, TypeInferenceContext tic, AParametersCollection methodParameters)
		{
			int params_arguments_start;
			if (methodParameters.HasParams) {
				params_arguments_start = methodParameters.Count - 1;
			} else {
				params_arguments_start = arg_count;
			}

			TypeSpec [] ptypes = methodParameters.Types;
			
			//
			// The first inference phase
			//
			TypeSpec method_parameter = null;
			for (int i = 0; i < arg_count; i++) {
				Argument a = arguments [i];
				if (a == null)
					continue;
				
				if (i < params_arguments_start) {
					method_parameter = methodParameters.Types [i];
				} else if (i == params_arguments_start) {
					if (arg_count == params_arguments_start + 1 && TypeManager.HasElementType (a.Type))
						method_parameter = methodParameters.Types [params_arguments_start];
					else
						method_parameter = TypeManager.GetElementType (methodParameters.Types [params_arguments_start]);

					ptypes = (TypeSpec[]) ptypes.Clone ();
					ptypes [i] = method_parameter;
				}

				//
				// When a lambda expression, an anonymous method
				// is used an explicit argument type inference takes a place
				//
				AnonymousMethodExpression am = a.Expr as AnonymousMethodExpression;
				if (am != null) {
					if (am.ExplicitTypeInference (ec, tic, method_parameter))
						--score; 
					continue;
				}

				if (a.IsByRef) {
					score -= tic.ExactInference (a.Type, method_parameter);
					continue;
				}

				if (a.Expr.Type == InternalType.Null)
					continue;

				if (TypeManager.IsValueType (method_parameter)) {
					score -= tic.LowerBoundInference (a.Type, method_parameter);
					continue;
				}

				//
				// Otherwise an output type inference is made
				//
				score -= tic.OutputTypeInference (ec, a.Expr, method_parameter);
			}

			//
			// Part of the second phase but because it happens only once
			// we don't need to call it in cycle
			//
			bool fixed_any = false;
			if (!tic.FixIndependentTypeArguments (ec, ptypes, ref fixed_any))
				return false;

			return DoSecondPhase (ec, tic, ptypes, !fixed_any);
		}

		//
		// Infers type arguments based on explicit arguments
		//
		public bool ExplicitTypeInference (ResolveContext ec, TypeInferenceContext type_inference, TypeSpec delegate_type)
		{
			if (!HasExplicitParameters)
				return false;

			if (!delegate_type.IsDelegate) {
				if (!delegate_type.IsExpressionTreeType)
					return false;

				delegate_type = TypeManager.GetTypeArguments (delegate_type) [0];
				if (!delegate_type.IsDelegate)
					return false;
			}
			
			AParametersCollection d_params = Delegate.GetParameters (delegate_type);
			if (d_params.Count != Parameters.Count)
				return false;

			for (int i = 0; i < Parameters.Count; ++i) {
				TypeSpec itype = d_params.Types [i];
				if (!TypeManager.IsGenericParameter (itype)) {
					if (!TypeManager.HasElementType (itype))
						continue;
					
					if (!TypeManager.IsGenericParameter (TypeManager.GetElementType (itype)))
					    continue;
				}
				type_inference.ExactInference (Parameters.Types [i], itype);
			}
			return true;
		}

		//
		// Infers type arguments based on explicit arguments
		//
		public bool ExplicitTypeInference (TypeInferenceContext type_inference, Type delegate_type)
		{
			if (!HasExplicitParameters)
				return false;

			if (!TypeManager.IsDelegateType (delegate_type)) {
#if GMCS_SOURCE
				if (TypeManager.DropGenericTypeArguments (delegate_type) != TypeManager.expression_type)
					return false;

				delegate_type = delegate_type.GetGenericArguments () [0];
				if (!TypeManager.IsDelegateType (delegate_type))
					return false;
#else
				return false;
#endif
			}
			
			AParametersCollection d_params = TypeManager.GetDelegateParameters (delegate_type);
			if (d_params.Count != Parameters.Count)
				return false;

			for (int i = 0; i < Parameters.Count; ++i) {
				Type itype = d_params.Types [i];
				if (!TypeManager.IsGenericParameter (itype)) {
					if (!TypeManager.HasElementType (itype))
						continue;
					
					if (!TypeManager.IsGenericParameter (itype.GetElementType ()))
					    continue;
				}
				type_inference.ExactInference (Parameters.Types [i], itype);
			}
			return true;
		}