Conversion MethodGroupConversion(ResolveResult resolveResult, IType toType) { // C# 4.0 spec §6.6 Method group conversions MethodGroupResolveResult rr = resolveResult as MethodGroupResolveResult; if (rr == null) { return(Conversion.None); } IMethod m = toType.GetDelegateInvokeMethod(); if (m == null) { return(Conversion.None); } ResolveResult[] args = new ResolveResult[m.Parameters.Count]; for (int i = 0; i < args.Length; i++) { IParameter param = m.Parameters[i]; IType parameterType = param.Type; if ((param.IsRef || param.IsOut) && parameterType.Kind == TypeKind.ByReference) { parameterType = ((ByReferenceType)parameterType).ElementType; args[i] = new ByReferenceResolveResult(parameterType, param.IsOut); } else { args[i] = new ResolveResult(parameterType); } } var or = rr.PerformOverloadResolution(compilation, args, allowExpandingParams: false, conversions: this); if (or.FoundApplicableCandidate) { IMethod method = (IMethod)or.GetBestCandidateWithSubstitutedTypeArguments(); var thisRR = rr.TargetResult as ThisResolveResult; bool isVirtual = method.IsOverridable && !(thisRR != null && thisRR.CausesNonVirtualInvocation); return(Conversion.MethodGroupConversion(method, isVirtual)); } else { return(Conversion.None); } }
Conversion MethodGroupConversion(ResolveResult resolveResult, IType toType) { // C# 4.0 spec §6.6 Method group conversions MethodGroupResolveResult rr = resolveResult as MethodGroupResolveResult; if (rr == null) { return(Conversion.None); } IMethod m = toType.GetDelegateInvokeMethod(); if (m == null) { return(Conversion.None); } ResolveResult[] args = new ResolveResult[m.Parameters.Count]; for (int i = 0; i < args.Length; i++) { IParameter param = m.Parameters[i]; IType parameterType = param.Type.Resolve(context); if ((param.IsRef || param.IsOut) && parameterType.Kind == TypeKind.ByReference) { parameterType = ((ByReferenceType)parameterType).ElementType; args[i] = new ByReferenceResolveResult(parameterType, param.IsOut); } else { args[i] = new ResolveResult(parameterType); } } var or = rr.PerformOverloadResolution(context, args, allowExpandingParams: false); if (or.FoundApplicableCandidate) { return(Conversion.MethodGroupConversion((IMethod)or.BestCandidate)); } else { return(Conversion.None); } }
void MakeOutputTypeInference(ResolveResult e, IType t) { Log.WriteLine(" MakeOutputTypeInference from " + e + " to " + t); // If E is an anonymous function with inferred return type U (§7.5.2.12) and T is a delegate type or expression // tree type with return type Tb, then a lower-bound inference (§7.5.2.9) is made from U to Tb. LambdaResolveResult lrr = e as LambdaResolveResult; if (lrr != null) { IMethod m = GetDelegateOrExpressionTreeSignature(t); if (m != null) { IType inferredReturnType; if (lrr.IsImplicitlyTyped) { if (m.Parameters.Count != lrr.Parameters.Count) { return; // cannot infer due to mismatched parameter lists } TypeParameterSubstitution substitution = GetSubstitutionForFixedTPs(); IType[] inferredParameterTypes = new IType[m.Parameters.Count]; for (int i = 0; i < inferredParameterTypes.Length; i++) { IType parameterType = m.Parameters[i].Type; inferredParameterTypes[i] = parameterType.AcceptVisitor(substitution); } inferredReturnType = lrr.GetInferredReturnType(inferredParameterTypes); } else { inferredReturnType = lrr.GetInferredReturnType(null); } MakeLowerBoundInference(inferredReturnType, m.ReturnType); return; } } // Otherwise, if E is a method group and T is a delegate type or expression tree type // with parameter types T1…Tk and return type Tb, and overload resolution // of E with the types T1…Tk yields a single method with return type U, then a lower-bound // inference is made from U to Tb. MethodGroupResolveResult mgrr = e as MethodGroupResolveResult; if (mgrr != null) { IMethod m = GetDelegateOrExpressionTreeSignature(t); if (m != null) { ResolveResult[] args = new ResolveResult[m.Parameters.Count]; TypeParameterSubstitution substitution = GetSubstitutionForFixedTPs(); for (int i = 0; i < args.Length; i++) { IParameter param = m.Parameters[i]; IType parameterType = param.Type.AcceptVisitor(substitution); if ((param.IsRef || param.IsOut) && parameterType.Kind == TypeKind.ByReference) { parameterType = ((ByReferenceType)parameterType).ElementType; args[i] = new ByReferenceResolveResult(parameterType, param.IsOut); } else { args[i] = new ResolveResult(parameterType); } } var or = mgrr.PerformOverloadResolution(compilation, args, allowExpandingParams: false, allowOptionalParameters: false); if (or.FoundApplicableCandidate && or.BestCandidateAmbiguousWith == null) { IType returnType = or.GetBestCandidateWithSubstitutedTypeArguments().ReturnType; MakeLowerBoundInference(returnType, m.ReturnType); } } return; } // Otherwise, if E is an expression with type U, then a lower-bound inference is made from U to T. if (IsValidType(e.Type)) { MakeLowerBoundInference(e.Type, t); } }