csharp-language-server-protocol

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Code for context:

[return: NotNullIfNotNull("items")]
public static implicit operator Container<T>?(T[] items) => items switch {
    not null => new Container<T>(items),
    _        => null
};

The annotation only accepts a non-null T[], so the _ branch of the switch cannot be used (assuming the caller is adhering to the annotated requirement).

However, this causes annoying workarounds when constructing objects where the value could be null, e.g:

string[]? commitCharacters = SomeCalculation();
CompletionItem c = new CompletionItem()
{
    ...,
    // error CS8604: Possible null reference argument for parameter 'items' in 'Container<string>.implicit operator Container<string>?(string[] items)'.
    CommitCharacters = commitCharacters,
    // alternatively, this can be written inconveniently as:
    CommitCharacters = commitCharacters ?? (Container<string>)null; // cast required to tell the compiler it isn't (string[])null
}

The same issue exists for the constructor, which prevents using new Container<string>(commitCharacters) either.