25public NullabilityInfo Nullability { get; } 38public NullabilityInfo ConvertedNullability { get; } 40internal TypeInfo(ITypeSymbol? type, ITypeSymbol? convertedType, NullabilityInfo nullability, NullabilityInfo convertedNullability)

12public readonly struct NullabilityInfo : IEquatable<NullabilityInfo> 37other is NullabilityInfo info && Equals(info); 42public bool Equals(NullabilityInfo other) =>

138public new NullabilityInfo TopLevelNullability

224protected NullabilityInfo TopLevelNullability 273private NullabilityInfo TopLevelNullabilityCore

94bool foundInfo = _updatedNullabilities.TryGetValue(currentBinary, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType); 155if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 258if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType))

968var nullabilityInfo = annotation.ToNullabilityInfo(declarationTypeSymbol); 2058NullabilityInfo nullability = boundExpr.TopLevelNullability; 2098NullabilityInfo convertedNullability; 2276static (TypeSymbol, NullabilityInfo) getTypeAndNullability(BoundExpression expr) => (expr.Type, expr.TopLevelNullability);

25public readonly NullabilityInfo Nullability; 33public readonly NullabilityInfo ConvertedNullability; 41internal CSharpTypeInfo(TypeSymbol type, TypeSymbol convertedType, NullabilityInfo nullability, NullabilityInfo convertedNullability, Conversion implicitConversion)

222private readonly ImmutableDictionary<BoundExpression, (NullabilityInfo Info, TypeSymbol? Type)>.Builder? _analyzedNullabilityMapOpt; 467ImmutableDictionary<BoundExpression, (NullabilityInfo, TypeSymbol?)>.Builder? analyzedNullabilityMapOpt, 1585ImmutableDictionary<BoundExpression, (NullabilityInfo, TypeSymbol?)> analyzedNullabilitiesMap; 1590private static (SnapshotManager?, ImmutableDictionary<BoundExpression, (NullabilityInfo, TypeSymbol?)>) AnalyzeWithSemanticInfo( 1600var analyzedNullabilities = ImmutableDictionary.CreateBuilder<BoundExpression, (NullabilityInfo, TypeSymbol?)>(EqualityComparer<BoundExpression>.Default, NullabilityInfoTypeComparer.Instance); 1658var analyzedNullabilities = ImmutableDictionary.CreateBuilder<BoundExpression, (NullabilityInfo, TypeSymbol?)>(EqualityComparer<BoundExpression>.Default, NullabilityInfoTypeComparer.Instance); 1698private static BoundNode Rewrite(ImmutableDictionary<BoundExpression, (NullabilityInfo, TypeSymbol?)> updatedNullabilities, SnapshotManager? snapshotManager, BoundNode node, ref ImmutableDictionary<Symbol, Symbol>? remappedSymbols) 1824ImmutableDictionary<BoundExpression, (NullabilityInfo, TypeSymbol?)>.Builder? analyzedNullabilityMapOpt, 13447private sealed class NullabilityInfoTypeComparer : IEqualityComparer<(NullabilityInfo info, TypeSymbol? type)> 13451public bool Equals((NullabilityInfo info, TypeSymbol? type) x, (NullabilityInfo info, TypeSymbol? type) y) 13457public int GetHashCode((NullabilityInfo info, TypeSymbol? type) obj)

21private readonly ImmutableDictionary<BoundExpression, (NullabilityInfo Info, TypeSymbol? Type)> _analyzedNullabilityMap; 26private DebugVerifier(ImmutableDictionary<BoundExpression, (NullabilityInfo Info, TypeSymbol? Type)> analyzedNullabilityMap, SnapshotManager? snapshotManager) 37public static void Verify(ImmutableDictionary<BoundExpression, (NullabilityInfo Info, TypeSymbol? Type)> analyzedNullabilityMap, SnapshotManager? snapshotManagerOpt, BoundNode node)

12389private readonly ImmutableDictionary<BoundExpression, (NullabilityInfo Info, TypeSymbol? Type)> _updatedNullabilities; 12393public NullabilityRewriter(ImmutableDictionary<BoundExpression, (NullabilityInfo Info, TypeSymbol? Type)> updatedNullabilities, NullableWalker.SnapshotManager? snapshotManager, ImmutableDictionary<Symbol, Symbol>.Builder remappedSymbols) 12426if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12441if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12458if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12472if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12484if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12496if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12508if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12520if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12532if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12544if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12556if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12568if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12580if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12592if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12607if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12625if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12643if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12657if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12669if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12687if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12711if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12728if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12745if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12763if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12780if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12798if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12816if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12834if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12851if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12868if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12886if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12905if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12923if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12941if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12959if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12979if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 12997if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13016if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13036if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13054if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13071if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13088if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13115if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13133if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13150if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13168if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13186if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13200if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13212if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13224if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13236if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13248if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13260if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13272if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13284if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13300if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13318if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13332if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13347if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13365if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13385if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13402if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13419if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13437if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13451if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13466if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13487if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13622if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13634if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13646if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13658if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13670if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13682if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13697if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13714if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13732if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13749if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13763if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13789if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13809if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13884if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13903if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13922if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13939if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13958if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13976if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 13996if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14010if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14026if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14046if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14064if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14084if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14103if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14122if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14139if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14159if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14176if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14199if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14213if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14228if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14246if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14265if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14282if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14300if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14319if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14336if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14354if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14373if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14392if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14406if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14423if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14440if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14457if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14475if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14493if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14510if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14529if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14548if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14566if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14583if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14601if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14619if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14639if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14657if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14676if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14695if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14712if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14733if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14750if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14767if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14784if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14798if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14810if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14827if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14846if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14980if (!_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 14995if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 15013if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 15031if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 15048if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 15074if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType)) 15093if (_updatedNullabilities.TryGetValue(node, out (NullabilityInfo Info, TypeSymbol? Type) infoAndType))

91internal static NullabilityInfo ToNullabilityInfo(this CodeAnalysis.NullableAnnotation annotation, TypeSymbol type) 102internal static NullabilityInfo ToNullabilityInfo(this NullableAnnotation annotation, TypeSymbol type)

146var nullability = typeInfo.Nullability;

22var notNullable = new NullabilityInfo(CodeAnalysis.NullableAnnotation.NotAnnotated, CodeAnalysis.NullableFlowState.NotNull); 23var nullable = new NullabilityInfo(CodeAnalysis.NullableAnnotation.Annotated, CodeAnalysis.NullableFlowState.MaybeNull);

1216var nullable = new NullabilityInfo(PublicNullableAnnotation.Annotated, PublicNullableFlowState.MaybeNull); 1217var notNullable = new NullabilityInfo(PublicNullableAnnotation.NotAnnotated, PublicNullableFlowState.NotNull); 1265var notNull = new NullabilityInfo(PublicNullableAnnotation.NotAnnotated, PublicNullableFlowState.NotNull); 1266var @null = new NullabilityInfo(PublicNullableAnnotation.Annotated, PublicNullableFlowState.MaybeNull);

211public NullabilityInfo Nullability; 213public NullabilityInfo ConvertedNullability;

18assertEqualsAndHashCode(default(NullabilityInfo), default(NullabilityInfo), equal: true); 31void assertEqualsAndHashCode(NullabilityInfo n1, NullabilityInfo n2, bool equal)