diff options
| author | Christian Rauch <Rauch.Christian@gmx.de> | 2022-07-05 10:55:48 +0100 |
|---|---|---|
| committer | Laurent Pinchart <laurent.pinchart@ideasonboard.com> | 2022-07-19 14:21:54 +0300 |
| commit | 1c4d4801850559d6f919eef5c2ffbaf7675dbc46 (patch) | |
| tree | d1686453c2d047565b9708bc9e03d375fcfa8578 /include | |
| parent | ef77e2637985b61dc99669b4396647ad13acb204 (diff) | |
libcamera: controls: Use std::optional to handle invalid control values
Previously, ControlList::get<T>() would use default constructed objects to
indicate that a ControlList does not have the requested Control. This has
several disadvantages: 1) It requires types to be default constructible,
2) it does not differentiate between a default constructed object and an
object that happens to have the same state as a default constructed object.
std::optional<T> additionally stores the information if the object is valid
or not, and therefore is more expressive than a default constructed object.
Signed-off-by: Christian Rauch <Rauch.Christian@gmx.de>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/libcamera/controls.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/include/libcamera/controls.h b/include/libcamera/controls.h index 665bcac1..192be784 100644 --- a/include/libcamera/controls.h +++ b/include/libcamera/controls.h @@ -8,6 +8,7 @@ #pragma once #include <assert.h> +#include <optional> #include <set> #include <stdint.h> #include <string> @@ -373,11 +374,11 @@ public: bool contains(unsigned int id) const; template<typename T> - T get(const Control<T> &ctrl) const + std::optional<T> get(const Control<T> &ctrl) const { const ControlValue *val = find(ctrl.id()); if (!val) - return T{}; + return std::nullopt; return val->get<T>(); } |