System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.CanOmitCast C# (CSharp) Method

        private static bool CanOmitCast(TypeUsage fromType, TypeUsage toType, bool preserveCastForDateTime)
        {
            var isPrimitiveType = TypeSemantics.IsPrimitiveType(fromType);

            //SQLBUDT #573573: This is to allow for a workaround on Katmai via explicit casting by the user.
            // The issue is that SqlServer's type Date maps to Edm.DateTime, same as SqlServer's DateTime and SmallDateTime.
            // However the conversion is not possible for all values of Date.

            //Note: we could also call here TypeSemantics.IsPrimitiveType(TypeUsage type, PrimitiveTypeKind primitiveTypeKind),
            //  but that checks again whether the type is primitive
            if (isPrimitiveType
                && preserveCastForDateTime
                && ((PrimitiveType)fromType.EdmType).PrimitiveTypeKind == PrimitiveTypeKind.DateTime)
            {
                return false;
            }

            if (TypeUsageEquals(fromType, toType))
            {
                return true;
            }

            if (isPrimitiveType)
            {
                return fromType.EdmType.EdmEquals(toType.EdmType);
            }

            return TypeSemantics.IsSubTypeOf(fromType, toType);
        }