| Message ID | 20210204035951.23751-2-laurent.pinchart@ideasonboard.com |
|---|---|
| State | Accepted |
| Commit | 515211e8efd1412c09ae0bd30b6382b27b85036f |
| Headers | show |
| Series |
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| Related | show |
Hi Laurent, Thanks for your patch. On 2021-02-04 05:59:51 +0200, Laurent Pinchart wrote: > Geometry classes generally have two sets of functions, one that operates > on the object and modifies it (e.g. Rectangle::scaleBy()), and one that > performs the same operations by instead return a modified copy of the > object, leaving the original untouched (e.g.Rectangle::scaledBy()). As > the names are close, they can easily be mistaken, with the const version > used instead of the in-place version. > > To catch these errors at compile time, mark the const versions with > __nodiscard, as there is no use case for calling them without using the > result of the call. > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Neat. Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> > --- > include/libcamera/geometry.h | 29 ++++++++++++++++------------- > 1 file changed, 16 insertions(+), 13 deletions(-) > > diff --git a/include/libcamera/geometry.h b/include/libcamera/geometry.h > index 2f3a82e2afc3..fdd1b4678074 100644 > --- a/include/libcamera/geometry.h > +++ b/include/libcamera/geometry.h > @@ -11,6 +11,8 @@ > #include <algorithm> > #include <string> > > +#include <libcamera/compiler.h> > + > namespace libcamera { > > class Rectangle; > @@ -92,8 +94,8 @@ public: > return *this; > } > > - constexpr Size alignedDownTo(unsigned int hAlignment, > - unsigned int vAlignment) const > + __nodiscard constexpr Size alignedDownTo(unsigned int hAlignment, > + unsigned int vAlignment) const > { > return { > width / hAlignment * hAlignment, > @@ -101,8 +103,8 @@ public: > }; > } > > - constexpr Size alignedUpTo(unsigned int hAlignment, > - unsigned int vAlignment) const > + __nodiscard constexpr Size alignedUpTo(unsigned int hAlignment, > + unsigned int vAlignment) const > { > return { > (width + hAlignment - 1) / hAlignment * hAlignment, > @@ -110,7 +112,7 @@ public: > }; > } > > - constexpr Size boundedTo(const Size &bound) const > + __nodiscard constexpr Size boundedTo(const Size &bound) const > { > return { > std::min(width, bound.width), > @@ -118,7 +120,7 @@ public: > }; > } > > - constexpr Size expandedTo(const Size &expand) const > + __nodiscard constexpr Size expandedTo(const Size &expand) const > { > return { > std::max(width, expand.width), > @@ -126,10 +128,10 @@ public: > }; > } > > - Size boundedToAspectRatio(const Size &ratio) const; > - Size expandedToAspectRatio(const Size &ratio) const; > + __nodiscard Size boundedToAspectRatio(const Size &ratio) const; > + __nodiscard Size expandedToAspectRatio(const Size &ratio) const; > > - Rectangle centeredTo(const Point ¢er) const; > + __nodiscard Rectangle centeredTo(const Point ¢er) const; > > Size operator*(float factor) const; > Size operator/(float factor) const; > @@ -247,10 +249,11 @@ public: > Rectangle &scaleBy(const Size &numerator, const Size &denominator); > Rectangle &translateBy(const Point &point); > > - Rectangle boundedTo(const Rectangle &bound) const; > - Rectangle enclosedIn(const Rectangle &boundary) const; > - Rectangle scaledBy(const Size &numerator, const Size &denominator) const; > - Rectangle translatedBy(const Point &point) const; > + __nodiscard Rectangle boundedTo(const Rectangle &bound) const; > + __nodiscard Rectangle enclosedIn(const Rectangle &boundary) const; > + __nodiscard Rectangle scaledBy(const Size &numerator, > + const Size &denominator) const; > + __nodiscard Rectangle translatedBy(const Point &point) const; > }; > > bool operator==(const Rectangle &lhs, const Rectangle &rhs); > -- > Regards, > > Laurent Pinchart > > _______________________________________________ > libcamera-devel mailing list > libcamera-devel@lists.libcamera.org > https://lists.libcamera.org/listinfo/libcamera-devel
On 04/02/2021 03:59, Laurent Pinchart wrote: > Geometry classes generally have two sets of functions, one that operates > on the object and modifies it (e.g. Rectangle::scaleBy()), and one that > performs the same operations by instead return a modified copy of the > object, leaving the original untouched (e.g.Rectangle::scaledBy()). As > the names are close, they can easily be mistaken, with the const version > used instead of the in-place version. > > To catch these errors at compile time, mark the const versions with > __nodiscard, as there is no use case for calling them without using the > result of the call. > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Getting the compiler to tell us when things are wrong early is always a win in my book: Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> With this, there is an existing usage of [[nodiscard]] in android/jpeg. I think it makes sense to keep the usage/style consistent, but that's not a change to go into this patch - so I've sent a separate patch in reply to this thread. Please pick it and apply with these if you feel it's appropriate and correct. -- Kieran > --- > include/libcamera/geometry.h | 29 ++++++++++++++++------------- > 1 file changed, 16 insertions(+), 13 deletions(-) > > diff --git a/include/libcamera/geometry.h b/include/libcamera/geometry.h > index 2f3a82e2afc3..fdd1b4678074 100644 > --- a/include/libcamera/geometry.h > +++ b/include/libcamera/geometry.h > @@ -11,6 +11,8 @@ > #include <algorithm> > #include <string> > > +#include <libcamera/compiler.h> > + > namespace libcamera { > > class Rectangle; > @@ -92,8 +94,8 @@ public: > return *this; > } > > - constexpr Size alignedDownTo(unsigned int hAlignment, > - unsigned int vAlignment) const > + __nodiscard constexpr Size alignedDownTo(unsigned int hAlignment, > + unsigned int vAlignment) const > { > return { > width / hAlignment * hAlignment, > @@ -101,8 +103,8 @@ public: > }; > } > > - constexpr Size alignedUpTo(unsigned int hAlignment, > - unsigned int vAlignment) const > + __nodiscard constexpr Size alignedUpTo(unsigned int hAlignment, > + unsigned int vAlignment) const > { > return { > (width + hAlignment - 1) / hAlignment * hAlignment, > @@ -110,7 +112,7 @@ public: > }; > } > > - constexpr Size boundedTo(const Size &bound) const > + __nodiscard constexpr Size boundedTo(const Size &bound) const > { > return { > std::min(width, bound.width), > @@ -118,7 +120,7 @@ public: > }; > } > > - constexpr Size expandedTo(const Size &expand) const > + __nodiscard constexpr Size expandedTo(const Size &expand) const > { > return { > std::max(width, expand.width), > @@ -126,10 +128,10 @@ public: > }; > } > > - Size boundedToAspectRatio(const Size &ratio) const; > - Size expandedToAspectRatio(const Size &ratio) const; > + __nodiscard Size boundedToAspectRatio(const Size &ratio) const; > + __nodiscard Size expandedToAspectRatio(const Size &ratio) const; > > - Rectangle centeredTo(const Point ¢er) const; > + __nodiscard Rectangle centeredTo(const Point ¢er) const; > > Size operator*(float factor) const; > Size operator/(float factor) const; > @@ -247,10 +249,11 @@ public: > Rectangle &scaleBy(const Size &numerator, const Size &denominator); > Rectangle &translateBy(const Point &point); > > - Rectangle boundedTo(const Rectangle &bound) const; > - Rectangle enclosedIn(const Rectangle &boundary) const; > - Rectangle scaledBy(const Size &numerator, const Size &denominator) const; > - Rectangle translatedBy(const Point &point) const; > + __nodiscard Rectangle boundedTo(const Rectangle &bound) const; > + __nodiscard Rectangle enclosedIn(const Rectangle &boundary) const; > + __nodiscard Rectangle scaledBy(const Size &numerator, > + const Size &denominator) const; > + __nodiscard Rectangle translatedBy(const Point &point) const; > }; > > bool operator==(const Rectangle &lhs, const Rectangle &rhs); >
diff --git a/include/libcamera/geometry.h b/include/libcamera/geometry.h index 2f3a82e2afc3..fdd1b4678074 100644 --- a/include/libcamera/geometry.h +++ b/include/libcamera/geometry.h @@ -11,6 +11,8 @@ #include <algorithm> #include <string> +#include <libcamera/compiler.h> + namespace libcamera { class Rectangle; @@ -92,8 +94,8 @@ public: return *this; } - constexpr Size alignedDownTo(unsigned int hAlignment, - unsigned int vAlignment) const + __nodiscard constexpr Size alignedDownTo(unsigned int hAlignment, + unsigned int vAlignment) const { return { width / hAlignment * hAlignment, @@ -101,8 +103,8 @@ public: }; } - constexpr Size alignedUpTo(unsigned int hAlignment, - unsigned int vAlignment) const + __nodiscard constexpr Size alignedUpTo(unsigned int hAlignment, + unsigned int vAlignment) const { return { (width + hAlignment - 1) / hAlignment * hAlignment, @@ -110,7 +112,7 @@ public: }; } - constexpr Size boundedTo(const Size &bound) const + __nodiscard constexpr Size boundedTo(const Size &bound) const { return { std::min(width, bound.width), @@ -118,7 +120,7 @@ public: }; } - constexpr Size expandedTo(const Size &expand) const + __nodiscard constexpr Size expandedTo(const Size &expand) const { return { std::max(width, expand.width), @@ -126,10 +128,10 @@ public: }; } - Size boundedToAspectRatio(const Size &ratio) const; - Size expandedToAspectRatio(const Size &ratio) const; + __nodiscard Size boundedToAspectRatio(const Size &ratio) const; + __nodiscard Size expandedToAspectRatio(const Size &ratio) const; - Rectangle centeredTo(const Point ¢er) const; + __nodiscard Rectangle centeredTo(const Point ¢er) const; Size operator*(float factor) const; Size operator/(float factor) const; @@ -247,10 +249,11 @@ public: Rectangle &scaleBy(const Size &numerator, const Size &denominator); Rectangle &translateBy(const Point &point); - Rectangle boundedTo(const Rectangle &bound) const; - Rectangle enclosedIn(const Rectangle &boundary) const; - Rectangle scaledBy(const Size &numerator, const Size &denominator) const; - Rectangle translatedBy(const Point &point) const; + __nodiscard Rectangle boundedTo(const Rectangle &bound) const; + __nodiscard Rectangle enclosedIn(const Rectangle &boundary) const; + __nodiscard Rectangle scaledBy(const Size &numerator, + const Size &denominator) const; + __nodiscard Rectangle translatedBy(const Point &point) const; }; bool operator==(const Rectangle &lhs, const Rectangle &rhs);
Geometry classes generally have two sets of functions, one that operates on the object and modifies it (e.g. Rectangle::scaleBy()), and one that performs the same operations by instead return a modified copy of the object, leaving the original untouched (e.g.Rectangle::scaledBy()). As the names are close, they can easily be mistaken, with the const version used instead of the in-place version. To catch these errors at compile time, mark the const versions with __nodiscard, as there is no use case for calling them without using the result of the call. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> --- include/libcamera/geometry.h | 29 ++++++++++++++++------------- 1 file changed, 16 insertions(+), 13 deletions(-)