Remove the verbose #ifndef/#define/#endif pattern for maintaining
header idempotency, and replace it with a simple #pragma once.
This simplifies the headers, and prevents redundant changes when
header files get moved.
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
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>
