I am using the MongoDB C# client to construct queries like "Name > 'Aardvark'".  I can easily create a query that filters on strings case-sensitively, like this:

return Builders<T>.Filter.Gt("Name", "Aardvark");

I can't seem to find an option for comparing strings case insensitively.  If I was writing the query directly in MongoDB, the query would look like this:

{ $expr: { $gte: [ {{{ $strcasecmp: [ "$Name", "}}Aardvark"] }, 0 ] } }

It seems like it should be possible to do this with the .Where() function, but that function only recognizes `obj => obj.Name.Equals("Aardvark", OrdinalIgnoreCase)`.  It doesn't seem to permit any comparisons.

When I try the following, I get an error executing my query:

return Builders<T>.Filter.Where(x => String.Compare(x.Name, "Aardvark", OrdinalIgnoreCase);

Is there a better way to do this, or is this not implemented today?