f84522d7cd
When retrieving the value from a `ControlValue` usually one of two things happen: a small, trivially copyable object is returned by value; or a view into the internal buffer is provided. This is true for everything except strings, which are returned in `std::string`, incurring the overhead of string construction. To guarantee no potentially "expensive" copies, use `std::string_view` pointing to the internal buffer to return the value. This is similar to how other array-like types are returned with a `Span<>`. This is an API break, but its scope is limited to just `properties::Model`. Bug: https://bugs.libcamera.org/show_bug.cgi?id=256 Signed-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>