# RegexImplicitStreamSubscriptionAttribute.RegexImplicitStreamSubscriptionAttribute(string)

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.regeximplicitstreamsubscriptionattribute/) | [Constructors](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.regeximplicitstreamsubscriptionattribute/constructors/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Streaming/Predicates/StreamSubscriptionAttributes.cs#L119-L121)

```csharp
public RegexImplicitStreamSubscriptionAttribute(string pattern)
```

Allows to pass a regular expression to filter stream namespaces to subscribe to.

### Parameters

- `pattern` (`string`): The stream namespace regular expression filter.