public void ArrayToEnumerable()
{
ITypeParameter tp = new DefaultTypeParameter(compilation, EntityType.Method, 0, "T");
IType stringType = compilation.FindType(KnownTypeCode.String);
ITypeDefinition enumerableType = compilation.FindType(KnownTypeCode.IEnumerableOfT).GetDefinition();
bool success;
Assert.AreEqual(
new [] { stringType },
ti.InferTypeArguments(new [] { tp },
new [] { new ResolveResult(new ArrayType(compilation, stringType)) },
new [] { new ParameterizedType(enumerableType, new [] { tp }) },
out success));
Assert.IsTrue(success);
}
void RunTypeInference(Candidate candidate)
{
IMethod method = candidate.Member as IMethod;
if (method == null || method.TypeParameters.Count == 0)
{
if (explicitlyGivenTypeArguments != null)
{
// method does not expect type arguments, but was given some
candidate.AddError(OverloadResolutionErrors.WrongNumberOfTypeArguments);
}
return;
}
// The method is generic:
if (explicitlyGivenTypeArguments != null)
{
if (explicitlyGivenTypeArguments.Length == method.TypeParameters.Count)
{
candidate.InferredTypes = explicitlyGivenTypeArguments;
}
else
{
candidate.AddError(OverloadResolutionErrors.WrongNumberOfTypeArguments);
// wrong number of type arguments given, so truncate the list or pad with UnknownType
candidate.InferredTypes = new IType[method.TypeParameters.Count];
for (int i = 0; i < candidate.InferredTypes.Length; i++)
{
if (i < explicitlyGivenTypeArguments.Length)
{
candidate.InferredTypes[i] = explicitlyGivenTypeArguments[i];
}
else
{
candidate.InferredTypes[i] = SharedTypes.UnknownType;
}
}
}
}
else
{
TypeInference ti = new TypeInference(context, conversions);
bool success;
candidate.InferredTypes = ti.InferTypeArguments(method.TypeParameters, arguments, candidate.ParameterTypes, out success);
if (!success)
{
candidate.AddError(OverloadResolutionErrors.TypeInferenceFailed);
}
}
// Now substitute in the formal parameters:
var substitution = new ConstraintValidatingSubstitution(candidate.InferredTypes, this);
for (int i = 0; i < candidate.ParameterTypes.Length; i++)
{
candidate.ParameterTypes[i] = candidate.ParameterTypes[i].AcceptVisitor(substitution);
}
if (!substitution.ConstraintsValid)
{
candidate.AddError(OverloadResolutionErrors.ConstructedTypeDoesNotSatisfyConstraint);
}
}
public void ArrayToEnumerable()
{
ITypeParameter tp = new DefaultTypeParameter(EntityType.Method, 0, "T");
IType stringType = KnownTypeReference.String.Resolve(ctx);
ITypeDefinition enumerableType = ctx.GetTypeDefinition(typeof(IEnumerable <>));
bool success;
Assert.AreEqual(
new [] { stringType },
ti.InferTypeArguments(new [] { tp },
new [] { new ResolveResult(new ArrayType(stringType)) },
new [] { new ParameterizedType(enumerableType, new [] { tp }) },
out success));
Assert.IsTrue(success);
}
void RunTypeInference(Candidate candidate)
{
if (candidate.TypeParameters == null)
{
if (explicitlyGivenTypeArguments != null)
{
// method does not expect type arguments, but was given some
candidate.AddError(OverloadResolutionErrors.WrongNumberOfTypeArguments);
}
// Grab new parameter types:
ResolveParameterTypes(candidate, true);
return;
}
ParameterizedType parameterizedDeclaringType = candidate.Member.DeclaringType as ParameterizedType;
IList <IType> classTypeArguments;
if (parameterizedDeclaringType != null)
{
classTypeArguments = parameterizedDeclaringType.TypeArguments;
}
else
{
classTypeArguments = null;
}
// The method is generic:
if (explicitlyGivenTypeArguments != null)
{
if (explicitlyGivenTypeArguments.Length == candidate.TypeParameters.Count)
{
candidate.InferredTypes = explicitlyGivenTypeArguments;
}
else
{
candidate.AddError(OverloadResolutionErrors.WrongNumberOfTypeArguments);
// wrong number of type arguments given, so truncate the list or pad with UnknownType
candidate.InferredTypes = new IType[candidate.TypeParameters.Count];
for (int i = 0; i < candidate.InferredTypes.Length; i++)
{
if (i < explicitlyGivenTypeArguments.Length)
{
candidate.InferredTypes[i] = explicitlyGivenTypeArguments[i];
}
else
{
candidate.InferredTypes[i] = SpecialType.UnknownType;
}
}
}
}
else
{
TypeInference ti = new TypeInference(compilation, conversions);
bool success;
candidate.InferredTypes = ti.InferTypeArguments(candidate.TypeParameters, arguments, candidate.ParameterTypes, out success, classTypeArguments);
if (!success)
{
candidate.AddError(OverloadResolutionErrors.TypeInferenceFailed);
}
}
// Now substitute in the formal parameters:
var substitution = new ConstraintValidatingSubstitution(classTypeArguments, candidate.InferredTypes, this);
for (int i = 0; i < candidate.ParameterTypes.Length; i++)
{
candidate.ParameterTypes[i] = candidate.ParameterTypes[i].AcceptVisitor(substitution);
}
if (!substitution.ConstraintsValid)
{
candidate.AddError(OverloadResolutionErrors.ConstructedTypeDoesNotSatisfyConstraint);
}
}
void RunTypeInference(Candidate candidate)
{
IMethod method = candidate.Member as IMethod;
if (method == null || method.TypeParameters.Count == 0) {
if (explicitlyGivenTypeArguments != null) {
// method does not expect type arguments, but was given some
candidate.AddError(OverloadResolutionErrors.WrongNumberOfTypeArguments);
}
return;
}
ParameterizedType parameterizedDeclaringType = candidate.Member.DeclaringType as ParameterizedType;
IList<IType> classTypeArguments;
if (parameterizedDeclaringType != null) {
classTypeArguments = parameterizedDeclaringType.TypeArguments;
} else {
classTypeArguments = null;
}
// The method is generic:
if (explicitlyGivenTypeArguments != null) {
if (explicitlyGivenTypeArguments.Length == method.TypeParameters.Count) {
candidate.InferredTypes = explicitlyGivenTypeArguments;
} else {
candidate.AddError(OverloadResolutionErrors.WrongNumberOfTypeArguments);
// wrong number of type arguments given, so truncate the list or pad with UnknownType
candidate.InferredTypes = new IType[method.TypeParameters.Count];
for (int i = 0; i < candidate.InferredTypes.Length; i++) {
if (i < explicitlyGivenTypeArguments.Length)
candidate.InferredTypes[i] = explicitlyGivenTypeArguments[i];
else
candidate.InferredTypes[i] = SpecialType.UnknownType;
}
}
} else {
TypeInference ti = new TypeInference(compilation, conversions);
bool success;
candidate.InferredTypes = ti.InferTypeArguments(candidate.TypeParameters, arguments, candidate.ParameterTypes, out success, classTypeArguments);
if (!success)
candidate.AddError(OverloadResolutionErrors.TypeInferenceFailed);
}
// Now substitute in the formal parameters:
var substitution = new ConstraintValidatingSubstitution(classTypeArguments, candidate.InferredTypes, this);
for (int i = 0; i < candidate.ParameterTypes.Length; i++) {
candidate.ParameterTypes[i] = candidate.ParameterTypes[i].AcceptVisitor(substitution);
}
if (!substitution.ConstraintsValid)
candidate.AddError(OverloadResolutionErrors.ConstructedTypeDoesNotSatisfyConstraint);
}
static bool IsEligibleExtensionMethod(ICompilation compilation, CSharpConversions conversions, IType targetType, IMethod method, bool useTypeInference, out IType[] outInferredTypes)
{
outInferredTypes = null;
if (targetType == null)
return true;
if (method.Parameters.Count == 0)
return false;
IType thisParameterType = method.Parameters[0].Type;
if (useTypeInference && method.TypeParameters.Count > 0) {
// We need to infer type arguments from targetType:
TypeInference ti = new TypeInference(compilation, conversions);
ResolveResult[] arguments = { new ResolveResult(targetType) };
IType[] parameterTypes = { method.Parameters[0].Type };
bool success;
var inferredTypes = ti.InferTypeArguments(method.TypeParameters, arguments, parameterTypes, out success);
var substitution = new TypeParameterSubstitution(null, inferredTypes);
// Validate that the types that could be inferred (aren't unknown) satisfy the constraints:
bool hasInferredTypes = false;
for (int i = 0; i < inferredTypes.Length; i++) {
if (inferredTypes[i].Kind != TypeKind.Unknown && inferredTypes[i].Kind != TypeKind.UnboundTypeArgument) {
hasInferredTypes = true;
if (!OverloadResolution.ValidateConstraints(method.TypeParameters[i], inferredTypes[i], substitution, conversions))
return false;
} else {
inferredTypes[i] = method.TypeParameters[i]; // do not substitute types that could not be inferred
}
}
if (hasInferredTypes)
outInferredTypes = inferredTypes;
thisParameterType = thisParameterType.AcceptVisitor(substitution);
}
Conversion c = conversions.ImplicitConversion(targetType, thisParameterType);
return c.IsValid && (c.IsIdentityConversion || c.IsReferenceConversion || c.IsBoxingConversion);
}
