libcamera: Add macro to conditionally use [[nodiscard]]

The [[nodiscard]] attribute has been added to C++17. It can thus be used
inside libcamera, but would prevent applications compiled for C++14 to
use libcamera if the attribute was used in public headers.

To offer this feature when the application is compiled with a
recent-enough C++ version, as well as for compiling libcamera itself,
add a __nodiscard macro that expands as [[nodiscard]] when using C++17
or newer.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

0 files changed, 0 insertions, 0 deletions