diff --git a/proposals/csharp-12.0/collection-expressions.md b/proposals/csharp-12.0/collection-expressions.md index 8db572e369..35e45803c8 100644 --- a/proposals/csharp-12.0/collection-expressions.md +++ b/proposals/csharp-12.0/collection-expressions.md @@ -176,7 +176,7 @@ For the *create method*: Determination of the *element type*: * If the collection type has an [*iteration type*](https://github.com/dotnet/csharpstandard/blob/standard-v6/standard/statements.md#1295-the-foreach-statement) (with above restriction) then the *element type* is the *iteration type*. -* Otherwise, if there is a single *create method* then the *element type* is `E` given by the method's only parameter (of type `System.ReadOnlySpan`). +* Otherwise, if there is a single non-generic *create method* then the *element type* is `E` given by the method's only parameter (of type `System.ReadOnlySpan`). An error is reported if the `[CollectionBuilder]` attribute does not refer to an invocable method with the expected signature.