internal override ImmutableArray <TypeWithAnnotations> GetConstraintTypes(ConsList <TypeParameterSymbol> inProgress, bool canIgnoreNullableContext)
{
var constraintTypes = ArrayBuilder <TypeWithAnnotations> .GetInstance();
_map.SubstituteConstraintTypesDistinctWithoutModifiers(_underlyingTypeParameter, _underlyingTypeParameter.GetConstraintTypes(inProgress, canIgnoreNullableContext), constraintTypes, null);
TypeWithAnnotations bestObjectConstraint = default;
// Strip all Object constraints.
for (int i = constraintTypes.Count - 1; i >= 0; i--)
{
TypeWithAnnotations type = constraintTypes[i];
if (ConstraintsHelper.IsObjectConstraint(type, ref bestObjectConstraint))
{
constraintTypes.RemoveAt(i);
}
}
if (bestObjectConstraint.HasType)
{
// See if we need to put Object! or Object~ back in order to preserve nullability information for the type parameter.
if (!canIgnoreNullableContext && ConstraintsHelper.IsObjectConstraintSignificant(CalculateIsNotNullableFromNonTypeConstraints(), bestObjectConstraint))
{
Debug.Assert(!HasNotNullConstraint && !HasValueTypeConstraint);
if (constraintTypes.Count == 0)
{
if (bestObjectConstraint.NullableAnnotation.IsOblivious() && !HasReferenceTypeConstraint)
{
bestObjectConstraint = default;
}
}
else
{
foreach (TypeWithAnnotations constraintType in constraintTypes)
{
if (!ConstraintsHelper.IsObjectConstraintSignificant(IsNotNullableFromConstraintType(constraintType, out _), bestObjectConstraint))
{
bestObjectConstraint = default;
break;
}
}
}
if (bestObjectConstraint.HasType)
{
constraintTypes.Insert(0, bestObjectConstraint);
}
}
}
return(constraintTypes.ToImmutableAndFree());
}