private bool bindExplicitConversionFromArrayToArray(ArrayType arraySrc, ArrayType arrayDest)
{
// 13.2.2
//
// The explicit reference conversions are:
//
// * From an array-type S with an element type SE to an array-type T with an element type
// TE, provided all of the following are true:
//
// * S and T differ only in element type. (In other words, S and T have the same number
// of dimensions.)
//
// * An explicit reference conversion exists from SE to TE.
if (arraySrc.rank != arrayDest.rank || arraySrc.IsSZArray != arrayDest.IsSZArray)
{
return(false); // Ranks do not match.
}
if (CConversions.FExpRefConv(GetSymbolLoader(), arraySrc.GetElementType(), arrayDest.GetElementType()))
{
if (_needsExprDest)
{
_binder.bindSimpleCast(_exprSrc, _exprTypeDest, out _exprDest, EXPRFLAG.EXF_REFCHECK);
}
return(true);
}
return(false);
}
private bool TryArrayVarianceAdjustmentToGetAccessibleType(CSemanticChecker semanticChecker, BindingContext bindingContext, ArrayType typeSrc, out CType typeDst)
{
Debug.Assert(typeSrc != null);
typeDst = null;
// We are here because we have an array type with an inaccessible element type. If possible,
// we should create a new array type that has an accessible element type for which a
// conversion exists.
CType elementType = typeSrc.GetElementType();
if (!elementType.IsRefType())
{
// Covariant array conversions exist for reference types only.
return(false);
}
CType intermediateType;
if (GetBestAccessibleType(semanticChecker, bindingContext, elementType, out intermediateType))
{
typeDst = this.GetArray(intermediateType, typeSrc.rank, typeSrc.IsSZArray);
Debug.Assert(semanticChecker.CheckTypeAccess(typeDst, bindingContext.ContextForMemberLookup));
return(true);
}
return(false);
}
private bool HasCovariantArrayConversion(ArrayType pSource, ArrayType pDest)
{
Debug.Assert(pSource != null);
Debug.Assert(pDest != null);
// * S and T differ only in element type. In other words, S and T have the same number of dimensions.
// * Both SE and TE are reference types.
// * An implicit reference conversion exists from SE to TE.
return((pSource.rank == pDest.rank) && pSource.IsSZArray == pDest.IsSZArray &&
HasImplicitReferenceConversion(pSource.GetElementType(), pDest.GetElementType()));
}
private static Type CalculateAssociatedSystemType(CType src)
{
Type result = null;
switch (src.GetTypeKind())
{
case TypeKind.TK_ArrayType:
ArrayType a = (ArrayType)src;
Type elementType = a.GetElementType().AssociatedSystemType;
result = a.IsSZArray ? elementType.MakeArrayType() : elementType.MakeArrayType(a.rank);
break;
case TypeKind.TK_NullableType:
NullableType n = (NullableType)src;
Type underlyingType = n.GetUnderlyingType().AssociatedSystemType;
result = typeof(Nullable <>).MakeGenericType(underlyingType);
break;
case TypeKind.TK_PointerType:
PointerType p = (PointerType)src;
Type referentType = p.GetReferentType().AssociatedSystemType;
result = referentType.MakePointerType();
break;
case TypeKind.TK_ParameterModifierType:
ParameterModifierType r = (ParameterModifierType)src;
Type parameterType = r.GetParameterType().AssociatedSystemType;
result = parameterType.MakeByRefType();
break;
case TypeKind.TK_AggregateType:
result = CalculateAssociatedSystemTypeForAggregate((AggregateType)src);
break;
case TypeKind.TK_TypeParameterType:
TypeParameterType t = (TypeParameterType)src;
if (t.IsMethodTypeParameter())
{
MethodInfo meth = ((MethodSymbol)t.GetOwningSymbol()).AssociatedMemberInfo as MethodInfo;
result = meth.GetGenericArguments()[t.GetIndexInOwnParameters()];
}
else
{
Type parentType = ((AggregateSymbol)t.GetOwningSymbol()).AssociatedSystemType;
result = parentType.GetGenericArguments()[t.GetIndexInOwnParameters()];
}
break;
}
Debug.Assert(result != null || src.GetTypeKind() == TypeKind.TK_AggregateType);
return(result);
}
public ArrayType GetArray(CType elementType, int args, bool isSZArray)
{
Name name;
Debug.Assert(args > 0 && args < 32767);
Debug.Assert(args == 1 || !isSZArray);
switch (args)
{
case 1:
if (isSZArray)
{
goto case 2;
}
else
{
goto default;
}
case 2:
name = NameManager.GetPredefinedName(PredefinedName.PN_ARRAY0 + args);
break;
default:
name = _BSymmgr.GetNameManager().Add("[X" + args + 1);
break;
}
// See if we already have an array type of this element type and rank.
ArrayType pArray = _typeTable.LookupArray(name, elementType);
if (pArray == null)
{
// No existing array symbol. Create a new one.
pArray = _typeFactory.CreateArray(name, elementType, args, isSZArray);
pArray.InitFromParent();
_typeTable.InsertArray(name, elementType, pArray);
}
else
{
Debug.Assert(pArray.HasErrors() == elementType.HasErrors());
}
Debug.Assert(pArray.rank == args);
Debug.Assert(pArray.GetElementType() == elementType);
return(pArray);
}
private bool HasArrayConversionToInterface(ArrayType pSource, CType pDest)
{
Debug.Assert(pSource != null);
Debug.Assert(pDest != null);
if (!pSource.IsSZArray)
{
return(false);
}
if (!pDest.isInterfaceType())
{
return(false);
}
// * From a single-dimensional array type S[] to IList<T> or IReadOnlyList<T> and their base
// interfaces, provided that there is an implicit identity or reference
// conversion from S to T.
// We only have six interfaces to check. IList<T>, IReadOnlyList<T> and their bases:
// * The base interface of IList<T> is ICollection<T>.
// * The base interface of ICollection<T> is IEnumerable<T>.
// * The base interface of IEnumerable<T> is IEnumerable.
// * The base interface of IReadOnlyList<T> is IReadOnlyCollection<T>.
// * The base interface of IReadOnlyCollection<T> is IEnumerable<T>.
if (pDest.isPredefType(PredefinedType.PT_IENUMERABLE))
{
return(true);
}
AggregateType atsDest = (AggregateType)pDest;
AggregateSymbol aggDest = atsDest.getAggregate();
if (!aggDest.isPredefAgg(PredefinedType.PT_G_ILIST) &&
!aggDest.isPredefAgg(PredefinedType.PT_G_ICOLLECTION) &&
!aggDest.isPredefAgg(PredefinedType.PT_G_IENUMERABLE) &&
!aggDest.isPredefAgg(PredefinedType.PT_G_IREADONLYCOLLECTION) &&
!aggDest.isPredefAgg(PredefinedType.PT_G_IREADONLYLIST))
{
return(false);
}
Debug.Assert(atsDest.GetTypeArgsAll().Count == 1);
CType pSourceElement = pSource.GetElementType();
CType pDestTypeArgument = atsDest.GetTypeArgsAll()[0];
return(HasIdentityOrImplicitReferenceConversion(pSourceElement, pDestTypeArgument));
}
private bool bindExplicitConversionFromIListToArray(ArrayType arrayDest)
{
// 13.2.2
//
// The explicit reference conversions are:
//
// * From System.Collections.Generic.IList<T>, System.Collections.Generic.IReadOnlyList<T> and their base interfaces
// to a one-dimensional array-type S[], provided there is an implicit or explicit reference conversion from
// S[] to System.Collections.Generic.IList<T> or System.Collections.Generic.IReadOnlyList<T>. This is precisely when either S and T
// are the same type or there is an implicit or explicit reference conversion from S to T.
if (!arrayDest.IsSZArray || !(_typeSrc is AggregateType aggSrc) || !aggSrc.isInterfaceType() ||
aggSrc.GetTypeArgsAll().Count != 1)
{
return(false);
}
AggregateSymbol aggIList = GetSymbolLoader().GetPredefAgg(PredefinedType.PT_G_ILIST);
AggregateSymbol aggIReadOnlyList = GetSymbolLoader().GetPredefAgg(PredefinedType.PT_G_IREADONLYLIST);
if ((aggIList == null ||
!GetSymbolLoader().IsBaseAggregate(aggIList, aggSrc.getAggregate())) &&
(aggIReadOnlyList == null ||
!GetSymbolLoader().IsBaseAggregate(aggIReadOnlyList, aggSrc.getAggregate())))
{
return(false);
}
CType typeArr = arrayDest.GetElementType();
CType typeLst = aggSrc.GetTypeArgsAll()[0];
Debug.Assert(!typeArr.IsNeverSameType());
if (typeArr != typeLst && !CConversions.FExpRefConv(GetSymbolLoader(), typeArr, typeLst))
{
return(false);
}
if (_needsExprDest)
{
_binder.bindSimpleCast(_exprSrc, _exprTypeDest, out _exprDest, EXPRFLAG.EXF_REFCHECK);
}
return(true);
}
private static Type CalculateAssociatedSystemType(CType src)
{
Type result = null;
switch (src.GetTypeKind())
{
case TypeKind.TK_ArrayType:
ArrayType a = src.AsArrayType();
Type elementType = a.GetElementType().AssociatedSystemType;
if (a.rank == 1)
{
result = elementType.MakeArrayType();
}
else
{
result = elementType.MakeArrayType(a.rank);
}
break;
case TypeKind.TK_NullableType:
NullableType n = src.AsNullableType();
Type underlyingType = n.GetUnderlyingType().AssociatedSystemType;
result = typeof(Nullable <>).MakeGenericType(underlyingType);
break;
case TypeKind.TK_PointerType:
PointerType p = src.AsPointerType();
Type referentType = p.GetReferentType().AssociatedSystemType;
result = referentType.MakePointerType();
break;
case TypeKind.TK_ParameterModifierType:
ParameterModifierType r = src.AsParameterModifierType();
Type parameterType = r.GetParameterType().AssociatedSystemType;
result = parameterType.MakeByRefType();
break;
case TypeKind.TK_AggregateType:
result = CalculateAssociatedSystemTypeForAggregate(src.AsAggregateType());
break;
case TypeKind.TK_TypeParameterType:
TypeParameterType t = src.AsTypeParameterType();
Type parentType = null;
if (t.IsMethodTypeParameter())
{
MethodInfo meth = t.GetOwningSymbol().AsMethodSymbol().AssociatedMemberInfo as MethodInfo;
result = meth.GetGenericArguments()[t.GetIndexInOwnParameters()];
}
else
{
parentType = t.GetOwningSymbol().AsAggregateSymbol().AssociatedSystemType;
result = parentType.GetTypeInfo().GenericTypeParameters[t.GetIndexInOwnParameters()];
}
break;
case TypeKind.TK_ArgumentListType:
case TypeKind.TK_BoundLambdaType:
case TypeKind.TK_ErrorType:
case TypeKind.TK_MethodGroupType:
case TypeKind.TK_NaturalIntegerType:
case TypeKind.TK_NullType:
case TypeKind.TK_OpenTypePlaceholderType:
case TypeKind.TK_UnboundLambdaType:
case TypeKind.TK_VoidType:
default:
break;
}
Debug.Assert(result != null || src.GetTypeKind() == TypeKind.TK_AggregateType);
return(result);
}
private bool bindExplicitConversionFromArrayToArray(ArrayType arraySrc, ArrayType arrayDest)
{
// 13.2.2
//
// The explicit reference conversions are:
//
// * From an array-type S with an element type SE to an array-type T with an element type
// TE, provided all of the following are true:
//
// * S and T differ only in element type. (In other words, S and T have the same number
// of dimensions.)
//
// * An explicit reference conversion exists from SE to TE.
if (arraySrc.rank != arrayDest.rank)
{
return false; // Ranks do not match.
}
if (CConversions.FExpRefConv(GetSymbolLoader(), arraySrc.GetElementType(), arrayDest.GetElementType()))
{
if (_needsExprDest)
_binder.bindSimpleCast(_exprSrc, _exprTypeDest, out _exprDest, EXPRFLAG.EXF_REFCHECK);
return true;
}
return false;
}
private bool bindExplicitConversionFromIListToArray(ArrayType arrayDest)
{
// 13.2.2
//
// The explicit reference conversions are:
//
// * From System.Collections.Generic.IList<T>, System.Collections.Generic.IReadOnlyList<T> and their base interfaces
// to a one-dimensional array-type S[], provided there is an implicit or explicit reference conversion from
// S[] to System.Collections.Generic.IList<T> or System.Collections.Generic.IReadOnlyList<T>. This is precisely when either S and T
// are the same type or there is an implicit or explicit reference conversion from S to T.
if (arrayDest.rank != 1 || !_typeSrc.isInterfaceType() ||
_typeSrc.AsAggregateType().GetTypeArgsAll().Size != 1)
{
return false;
}
AggregateSymbol aggIList = GetSymbolLoader().GetOptPredefAgg(PredefinedType.PT_G_ILIST);
AggregateSymbol aggIReadOnlyList = GetSymbolLoader().GetOptPredefAgg(PredefinedType.PT_G_IREADONLYLIST);
if ((aggIList == null ||
!GetSymbolLoader().IsBaseAggregate(aggIList, _typeSrc.AsAggregateType().getAggregate())) &&
(aggIReadOnlyList == null ||
!GetSymbolLoader().IsBaseAggregate(aggIReadOnlyList, _typeSrc.AsAggregateType().getAggregate())))
{
return false;
}
CType typeArr = arrayDest.GetElementType();
CType typeLst = _typeSrc.AsAggregateType().GetTypeArgsAll().Item(0);
Debug.Assert(!typeArr.IsNeverSameType());
if (typeArr != typeLst && !CConversions.FExpRefConv(GetSymbolLoader(), typeArr, typeLst))
{
return false;
}
if (_needsExprDest)
_binder.bindSimpleCast(_exprSrc, _exprTypeDest, out _exprDest, EXPRFLAG.EXF_REFCHECK);
return true;
}
private bool TryArrayVarianceAdjustmentToGetAccessibleType(CSemanticChecker semanticChecker, BindingContext bindingContext, ArrayType typeSrc, out CType typeDst)
{
Debug.Assert(typeSrc != null);
typeDst = null;
// We are here because we have an array type with an inaccessible element type. If possible,
// we should create a new array type that has an accessible element type for which a
// conversion exists.
CType elementType = typeSrc.GetElementType();
if (!elementType.IsRefType())
{
// Covariant array conversions exist for reference types only.
return false;
}
CType intermediateType;
if (GetBestAccessibleType(semanticChecker, bindingContext, elementType, out intermediateType))
{
typeDst = this.GetArray(intermediateType, typeSrc.rank);
Debug.Assert(semanticChecker.CheckTypeAccess(typeDst, bindingContext.ContextForMemberLookup()));
return true;
}
return false;
}
/***************************************************************************************************
* Determine whether there is an explicit or implicit reference conversion (or identity conversion)
* from typeSrc to typeDst. This is when:
*
* 13.2.3 Explicit reference conversions
*
* The explicit reference conversions are:
* From object to any reference-type.
* From any class-type S to any class-type T, provided S is a base class of T.
* From any class-type S to any interface-type T, provided S is not sealed and provided S does not implement T.
* From any interface-type S to any class-type T, provided T is not sealed or provided T implements S.
* From any interface-type S to any interface-type T, provided S is not derived from T.
* From an array-type S with an element type SE to an array-type T with an element type TE, provided all of the following are true:
* o S and T differ only in element type. (In other words, S and T have the same number of dimensions.)
* o An explicit reference conversion exists from SE to TE.
* From System.Array and the interfaces it implements, to any array-type.
* From System.Delegate and the interfaces it implements, to any delegate-type.
* From a one-dimensional array-type S[] to System.Collections.Generic.IList<T>, System.Collections.Generic.IReadOnlyList<T> and their base interfaces, provided there is an explicit reference conversion from S to T.
* From a generic delegate type S to generic delegate type T, provided all of the follow are true:
* o Both types are constructed generic types of the same generic delegate type, D<X1,... Xk>.That is,
* S is D<S1,... Sk> and T is D<T1,... Tk>.
* o S is not compatible with or identical to T.
* o If type parameter Xi is declared to be invariant then Si must be identical to Ti.
* o If type parameter Xi is declared to be covariant ("out") then Si must be convertible
* to Ti via an identify conversion, implicit reference conversion, or explicit reference conversion.
* o If type parameter Xi is declared to be contravariant ("in") then either Si must be identical to Ti,
* or Si and Ti must both be reference types.
* From System.Collections.Generic.IList<T>, System.Collections.Generic.IReadOnlyList<T> and their base interfaces to a one-dimensional array-type S[], provided there is an implicit or explicit reference conversion from S[] to System.Collections.Generic.IList<T> or System.Collections.Generic.IReadOnlyList<T>. This is precisely when either S and T are the same type or there is an implicit or explicit reference conversion from S to T.
*
* For a type-parameter T that is known to be a reference type (§25.7), the following explicit reference conversions exist:
* From the effective base class C of T to T and from any base class of C to T.
* From any interface-type to T.
* From T to any interface-type I provided there isn’t already an implicit reference conversion from T to I.
* From a type-parameter U to T provided that T depends on U (§25.7). [Note: Since T is known to be a reference type, within the scope of T, the run-time type of U will always be a reference type, even if U is not known to be a reference type at compile-time. end note]
*
* Both src and dst are reference types and there is a builtin explicit conversion from
* src to dst.
* Or src is a reference type and dst is a base type of src (in which case the conversion is
* implicit as well).
* Or dst is a reference type and src is a base type of dst.
*
* The latter two cases can happen with type variables even though the other type variable is not
* a reference type.
***************************************************************************************************/
public static bool FExpRefConv(SymbolLoader loader, CType typeSrc, CType typeDst)
{
Debug.Assert(typeSrc != null);
Debug.Assert(typeDst != null);
if (typeSrc.IsRefType() && typeDst.IsRefType())
{
// is there an implicit reference conversion in either direction?
// this handles the bulk of the cases ...
if (loader.HasIdentityOrImplicitReferenceConversion(typeSrc, typeDst) ||
loader.HasIdentityOrImplicitReferenceConversion(typeDst, typeSrc))
{
return(true);
}
// For a type-parameter T that is known to be a reference type (§25.7), the following explicit reference conversions exist:
// • From any interface-type to T.
// • From T to any interface-type I provided there isn’t already an implicit reference conversion from T to I.
if (typeSrc.isInterfaceType() && typeDst.IsTypeParameterType())
{
return(true);
}
if (typeSrc.IsTypeParameterType() && typeDst.isInterfaceType())
{
return(true);
}
// * From any class-type S to any interface-type T, provided S is not sealed
// * From any interface-type S to any class-type T, provided T is not sealed
// * From any interface-type S to any interface-type T, provided S is not derived from T.
if (typeSrc.IsAggregateType() && typeDst.IsAggregateType())
{
AggregateSymbol aggSrc = typeSrc.AsAggregateType().getAggregate();
AggregateSymbol aggDest = typeDst.AsAggregateType().getAggregate();
if ((aggSrc.IsClass() && !aggSrc.IsSealed() && aggDest.IsInterface()) ||
(aggSrc.IsInterface() && aggDest.IsClass() && !aggDest.IsSealed()) ||
(aggSrc.IsInterface() && aggDest.IsInterface()))
{
return(true);
}
}
// * From an array-type S with an element type SE to an array-type T with an element type TE, provided all of the following are true:
// o S and T differ only in element type. (In other words, S and T have the same number of dimensions.)
// o An explicit reference conversion exists from SE to TE.
if (typeSrc.IsArrayType() && typeDst.IsArrayType())
{
return(typeSrc.AsArrayType().rank == typeDst.AsArrayType().rank&& FExpRefConv(loader, typeSrc.AsArrayType().GetElementType(), typeDst.AsArrayType().GetElementType()));
}
// * From a one-dimensional array-type S[] to System.Collections.Generic.IList<T>, System.Collections.Generic.IReadOnlyList<T>
// and their base interfaces, provided there is an explicit reference conversion from S to T.
if (typeSrc.IsArrayType())
{
if (typeSrc.AsArrayType().rank != 1 ||
!typeDst.isInterfaceType() || typeDst.AsAggregateType().GetTypeArgsAll().Size != 1)
{
return(false);
}
AggregateSymbol aggIList = loader.GetOptPredefAgg(PredefinedType.PT_G_ILIST);
AggregateSymbol aggIReadOnlyList = loader.GetOptPredefAgg(PredefinedType.PT_G_IREADONLYLIST);
if ((aggIList == null ||
!loader.IsBaseAggregate(aggIList, typeDst.AsAggregateType().getAggregate())) &&
(aggIReadOnlyList == null ||
!loader.IsBaseAggregate(aggIReadOnlyList, typeDst.AsAggregateType().getAggregate())))
{
return(false);
}
return(FExpRefConv(loader, typeSrc.AsArrayType().GetElementType(), typeDst.AsAggregateType().GetTypeArgsAll().Item(0)));
}
if (typeDst.IsArrayType() && typeSrc.IsAggregateType())
{
// * From System.Array and the interfaces it implements, to any array-type.
if (loader.HasIdentityOrImplicitReferenceConversion(loader.GetReqPredefType(PredefinedType.PT_ARRAY), typeSrc))
{
return(true);
}
// * From System.Collections.Generic.IList<T>, System.Collections.Generic.IReadOnlyList<T> and their base interfaces to a
// one-dimensional array-type S[], provided there is an implicit or explicit reference conversion from S[] to
// System.Collections.Generic.IList<T> or System.Collections.Generic.IReadOnlyList<T>. This is precisely when either S and T
// are the same type or there is an implicit or explicit reference conversion from S to T.
ArrayType arrayDest = typeDst.AsArrayType();
AggregateType aggtypeSrc = typeSrc.AsAggregateType();
if (arrayDest.rank != 1 || !typeSrc.isInterfaceType() ||
aggtypeSrc.GetTypeArgsAll().Size != 1)
{
return(false);
}
AggregateSymbol aggIList = loader.GetOptPredefAgg(PredefinedType.PT_G_ILIST);
AggregateSymbol aggIReadOnlyList = loader.GetOptPredefAgg(PredefinedType.PT_G_IREADONLYLIST);
if ((aggIList == null ||
!loader.IsBaseAggregate(aggIList, aggtypeSrc.getAggregate())) &&
(aggIReadOnlyList == null ||
!loader.IsBaseAggregate(aggIReadOnlyList, aggtypeSrc.getAggregate())))
{
return(false);
}
CType typeArr = arrayDest.GetElementType();
CType typeLst = aggtypeSrc.GetTypeArgsAll().Item(0);
Debug.Assert(!typeArr.IsNeverSameType());
return(typeArr == typeLst || FExpRefConv(loader, typeArr, typeLst));
}
if (HasGenericDelegateExplicitReferenceConversion(loader, typeSrc, typeDst))
{
return(true);
}
}
else if (typeSrc.IsRefType())
{
// conversion of T . U, where T : class, U
// .. these constraints implies where U : class
return(loader.HasIdentityOrImplicitReferenceConversion(typeSrc, typeDst));
}
else if (typeDst.IsRefType())
{
// conversion of T . U, where U : class, T
// .. these constraints implies where T : class
return(loader.HasIdentityOrImplicitReferenceConversion(typeDst, typeSrc));
}
return(false);
}
private bool HasArrayConversionToInterface(ArrayType pSource, CType pDest)
{
Debug.Assert(pSource != null);
Debug.Assert(pDest != null);
if (pSource.rank != 1)
{
return false;
}
if (!pDest.isInterfaceType())
{
return false;
}
// * From a single-dimensional array type S[] to IList<T> or IReadOnlyList<T> and their base
// interfaces, provided that there is an implicit identity or reference
// conversion from S to T.
// We only have six interfaces to check. IList<T>, IReadOnlyList<T> and their bases:
// * The base interface of IList<T> is ICollection<T>.
// * The base interface of ICollection<T> is IEnumerable<T>.
// * The base interface of IEnumerable<T> is IEnumerable.
// * The base interface of IReadOnlyList<T> is IReadOnlyCollection<T>.
// * The base interface of IReadOnlyCollection<T> is IEnumerable<T>.
if (pDest.isPredefType(PredefinedType.PT_IENUMERABLE))
{
return true;
}
AggregateType atsDest = pDest.AsAggregateType();
AggregateSymbol aggDest = pDest.getAggregate();
if (!aggDest.isPredefAgg(PredefinedType.PT_G_ILIST) &&
!aggDest.isPredefAgg(PredefinedType.PT_G_ICOLLECTION) &&
!aggDest.isPredefAgg(PredefinedType.PT_G_IENUMERABLE) &&
!aggDest.isPredefAgg(PredefinedType.PT_G_IREADONLYCOLLECTION) &&
!aggDest.isPredefAgg(PredefinedType.PT_G_IREADONLYLIST))
{
return false;
}
Debug.Assert(atsDest.GetTypeArgsAll().Size == 1);
CType pSourceElement = pSource.GetElementType();
CType pDestTypeArgument = atsDest.GetTypeArgsAll().Item(0);
return HasIdentityOrImplicitReferenceConversion(pSourceElement, pDestTypeArgument);
}
private bool HasCovariantArrayConversion(ArrayType pSource, ArrayType pDest)
{
Debug.Assert(pSource != null);
Debug.Assert(pDest != null);
// * S and T differ only in element type. In other words, S and T have the same number of dimensions.
// * Both SE and TE are reference types.
// * An implicit reference conversion exists from SE to TE.
return (pSource.rank == pDest.rank) &&
HasImplicitReferenceConversion(pSource.GetElementType(), pDest.GetElementType());
}
