[PATCH v1] libcamera: base: span: Explicitly default copy assignment

[Kieran Bingham]

Quoting Barnabás Pőcze (2025-03-10 17:03:56)
> The `dynamic_extent` specialization is currently not trivially copyable
> unlike its standard counterpart, `std::span`. This is because the copy
> assignment operator is user-defined. Explicitly default it just like
> it is done in the main template definition.
> 
> Signed-off-by: Barnabás Pőcze <barnabas.pocze at ideasonboard.com>
> ---
>  include/libcamera/base/span.h | 8 +-------
>  1 file changed, 1 insertion(+), 7 deletions(-)
> 
> diff --git a/include/libcamera/base/span.h b/include/libcamera/base/span.h
> index 92cce4f05..806db106e 100644
> --- a/include/libcamera/base/span.h
> +++ b/include/libcamera/base/span.h
> @@ -346,13 +346,7 @@ public:
>         }
>  
>         constexpr Span(const Span &other) noexcept = default;
> -
> -       constexpr Span &operator=(const Span &other) noexcept
> -       {
> -               data_ = other.data_;
> -               size_ = other.size_;
> -               return *this;
> -       }
> +       constexpr Span &operator=(const Span &other) noexcept = default;

This sounds sane, as the default copy should do identically as above I
think.

But wasn't there some rule of 5+-2 that says you're supposed to define
all if you define one ?

Is there any ABI breakage in this patch ? Or will it compile to
something directly compatible ?

For the change itself:

Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

But if it's an ABI change I'd like to batch up all the ABI changes
together.

--
Kieran


>  
>         constexpr iterator begin() const { return data(); }
>         constexpr const_iterator cbegin() const { return begin(); }
> -- 
> 2.48.1
>