// 13.2.2 Explicit enumeration conversions // // The explicit enumeration conversions are: // // * From sbyte, byte, short, ushort, int, uint, long, ulong, char, float, double, or // decimal to any enum-type. // // * From any enum-type to sbyte, byte, short, ushort, int, uint, long, ulong, char, // float, double, or decimal. // // * From any enum-type to any other enum-type. // // * An explicit enumeration conversion between two types is processed by treating any // participating enum-type as the underlying type of that enum-type, and then performing // an implicit or explicit numeric conversion between the resulting types. private AggCastResult bindExplicitConversionFromEnumToAggregate(AggregateType aggTypeDest) { Debug.Assert(_typeSrc != null); Debug.Assert(aggTypeDest != null); if (!_typeSrc.isEnumType()) { return(AggCastResult.Failure); } AggregateSymbol aggDest = aggTypeDest.getAggregate(); if (aggDest.isPredefAgg(PredefinedType.PT_DECIMAL)) { return(bindExplicitConversionFromEnumToDecimal(aggTypeDest)); } if (!aggDest.getThisType().isNumericType() && !aggDest.IsEnum() && !(aggDest.IsPredefined() && aggDest.GetPredefType() == PredefinedType.PT_CHAR)) { return(AggCastResult.Failure); } if (_exprSrc.GetConst() != null) { ConstCastResult result = _binder.bindConstantCast(_exprSrc, _exprTypeDest, _needsExprDest, out _exprDest, true); if (result == ConstCastResult.Success) { return(AggCastResult.Success); } else if (result == ConstCastResult.CheckFailure) { return(AggCastResult.Abort); } } if (_needsExprDest) { _binder.bindSimpleCast(_exprSrc, _exprTypeDest, out _exprDest); } return(AggCastResult.Success); }
private bool bindImplicitConversionBetweenSimpleTypes(AggregateType aggTypeSrc) { AggregateSymbol aggSrc = aggTypeSrc.getAggregate(); Debug.Assert(aggSrc.getThisType().isSimpleType()); Debug.Assert(_typeDest.isSimpleType()); Debug.Assert(aggSrc.IsPredefined() && _typeDest.isPredefined()); PredefinedType ptSrc = aggSrc.GetPredefType(); PredefinedType ptDest = _typeDest.getPredefType(); ConvKind convertKind; bool fConstShrinkCast = false; Debug.Assert((int)ptSrc < NUM_SIMPLE_TYPES && (int)ptDest < NUM_SIMPLE_TYPES); // 13.1.7 Implicit constant expression conversions // // An implicit constant expression conversion permits the following conversions: // * A constant-expression (14.16) of type int can be converted to type sbyte, byte, short, // ushort, uint, or ulong, provided the value of the constant-expression is within the range // of the destination type. // * A constant-expression of type long can be converted to type ulong, provided the value of // the constant-expression is not negative. // Note: Don't use GetConst here since the conversion only applies to bona-fide compile time constants. if (_exprSrc != null && _exprSrc.isCONSTANT_OK() && ((ptSrc == PredefinedType.PT_INT && ptDest != PredefinedType.PT_BOOL && ptDest != PredefinedType.PT_CHAR) || (ptSrc == PredefinedType.PT_LONG && ptDest == PredefinedType.PT_ULONG)) && isConstantInRange(_exprSrc.asCONSTANT(), _typeDest)) { // Special case (CLR 6.1.6): if integral constant is in range, the conversion is a legal implicit conversion. convertKind = ConvKind.Implicit; fConstShrinkCast = _needsExprDest && (GetConvKind(ptSrc, ptDest) != ConvKind.Implicit); } else if (ptSrc == ptDest) { // Special case: precision limiting casts to float or double Debug.Assert(ptSrc == PredefinedType.PT_FLOAT || ptSrc == PredefinedType.PT_DOUBLE); Debug.Assert(0 != (_flags & CONVERTTYPE.ISEXPLICIT)); convertKind = ConvKind.Implicit; } else { convertKind = GetConvKind(ptSrc, ptDest); Debug.Assert(convertKind != ConvKind.Identity); // identity conversion should have been handled at first. } if (convertKind != ConvKind.Implicit) { return(false); } // An implicit conversion exists. Do the conversion. if (_exprSrc.GetConst() != null) { // Fold the constant cast if possible. ConstCastResult result = _binder.bindConstantCast(_exprSrc, _exprTypeDest, _needsExprDest, out _exprDest, false); if (result == ConstCastResult.Success) { return(true); // else, don't fold and use a regular cast, below. } } if (isUserDefinedConversion(ptSrc, ptDest)) { if (!_needsExprDest) { return(true); } // According the language, this is a standard conversion, but it is implemented // through a user-defined conversion. Because it's a standard conversion, we don't // test the NOUDC flag here. return(_binder.bindUserDefinedConversion(_exprSrc, aggTypeSrc, _typeDest, _needsExprDest, out _exprDest, true)); } if (_needsExprDest) { _binder.bindSimpleCast(_exprSrc, _exprTypeDest, out _exprDest); } return(true); }