Physics shape rework #3: made shape constructors implicit.

Allows to use them in (future) ObjectShape construction without unneded
verbosity:

    new Physics::ObjectShape<Physics::Point2D>(o, {{1.0f, -2.5f}});

instead of:

    new Physics::ObjectShape<Physics::Point2D>(o, Physics::Point2D(...));

src/Physics/AxisAlignedBox.h

@@ -54,10 +54,10 @@ template<UnsignedInt dimensions> class MAGNUM_PHYSICS_EXPORT AxisAlignedBox {
          *
          * Creates zero sized box positioned at origin.
          */
-        inline constexpr explicit AxisAlignedBox() {}
+        inline constexpr /*implicit*/ AxisAlignedBox() {}
 
         /** @brief Constructor */
-        inline constexpr explicit AxisAlignedBox(const typename DimensionTraits<dimensions>::VectorType& min, const typename DimensionTraits<dimensions>::VectorType& max): _min(min), _max(max) {}
+        inline constexpr /*implicit*/ AxisAlignedBox(const typename DimensionTraits<dimensions>::VectorType& min, const typename DimensionTraits<dimensions>::VectorType& max): _min(min), _max(max) {}
 
         /** @brief Transformed shape */
         AxisAlignedBox<dimensions> transformed(const typename DimensionTraits<dimensions>::MatrixType& matrix) const;

src/Physics/Box.h

@@ -55,10 +55,10 @@ template<UnsignedInt dimensions> class MAGNUM_PHYSICS_EXPORT Box {
          *
          * Creates zero-sized box positioned at origin.
          */
-        inline constexpr explicit Box(): _transformation(DimensionTraits<dimensions>::MatrixType::Zero) {}
+        inline constexpr /*implicit*/ Box(): _transformation(DimensionTraits<dimensions>::MatrixType::Zero) {}
 
         /** @brief Constructor */
-        inline constexpr explicit Box(const typename DimensionTraits<dimensions>::MatrixType& transformation): _transformation(transformation) {}
+        inline constexpr /*implicit*/ Box(const typename DimensionTraits<dimensions>::MatrixType& transformation): _transformation(transformation) {}
 
         /** @brief Transformed shape */
         Box<dimensions> transformed(const typename DimensionTraits<dimensions>::MatrixType& matrix) const;

src/Physics/Capsule.h

@@ -54,10 +54,10 @@ template<UnsignedInt dimensions> class MAGNUM_PHYSICS_EXPORT Capsule {
          *
          * Creates zero-sized capsule at origin.
          */
-        inline constexpr explicit Capsule(): _radius(0.0f) {}
+        inline constexpr /*implicit*/ Capsule(): _radius(0.0f) {}
 
         /** @brief Constructor */
-        inline constexpr explicit Capsule(const typename DimensionTraits<dimensions>::VectorType& a, const typename DimensionTraits<dimensions>::VectorType& b, Float radius): _a(a), _b(b), _radius(radius) {}
+        inline constexpr /*implicit*/ Capsule(const typename DimensionTraits<dimensions>::VectorType& a, const typename DimensionTraits<dimensions>::VectorType& b, Float radius): _a(a), _b(b), _radius(radius) {}
 
         /** @brief Transformed shape */
         Capsule<dimensions> transformed(const typename DimensionTraits<dimensions>::MatrixType& matrix) const;

src/Physics/Line.h

@@ -51,10 +51,10 @@ template<UnsignedInt dimensions> class MAGNUM_PHYSICS_EXPORT Line {
          *
          * Creates line with both points at origin.
          */
-        inline constexpr explicit Line() {}
+        inline constexpr /*implicit*/ Line() {}
 
         /** @brief Constructor */
-        inline constexpr explicit Line(const typename DimensionTraits<dimensions>::VectorType& a, const typename DimensionTraits<dimensions>::VectorType& b): _a(a), _b(b) {}
+        inline constexpr /*implicit*/ Line(const typename DimensionTraits<dimensions>::VectorType& a, const typename DimensionTraits<dimensions>::VectorType& b): _a(a), _b(b) {}
 
         /** @brief Transformed shape */
         Line<dimensions> transformed(const typename DimensionTraits<dimensions>::MatrixType& matrix) const;

src/Physics/LineSegment.h

@@ -44,10 +44,10 @@ template<UnsignedInt dimensions> class LineSegment: public Line<dimensions> {
          *
          * Creates line segment with both points at origin.
          */
-        inline constexpr explicit LineSegment() {}
+        inline constexpr /*implicit*/ LineSegment() {}
 
         /** @brief Constructor */
-        inline constexpr explicit LineSegment(const typename DimensionTraits<dimensions>::VectorType& a, const typename DimensionTraits<dimensions>::VectorType& b): Line<dimensions>(a, b) {}
+        inline constexpr /*implicit*/ LineSegment(const typename DimensionTraits<dimensions>::VectorType& a, const typename DimensionTraits<dimensions>::VectorType& b): Line<dimensions>(a, b) {}
 
         /** @brief Transformed shape */
         inline LineSegment<dimensions> transformed(const typename DimensionTraits<dimensions>::MatrixType& matrix) const {

src/Physics/Plane.h

@@ -47,10 +47,10 @@ class MAGNUM_PHYSICS_EXPORT Plane {
          *
          * Creates plane with zero-sized normal at origin.
          */
-        inline constexpr explicit Plane() {}
+        inline constexpr /*implicit*/ Plane() {}
 
         /** @brief Constructor */
-        inline constexpr explicit Plane(const Vector3& position, const Vector3& normal): _position(position), _normal(normal) {}
+        inline constexpr /*implicit*/ Plane(const Vector3& position, const Vector3& normal): _position(position), _normal(normal) {}
 
         /** @brief Transformed shape */
         Plane transformed(const Matrix4& matrix) const;

src/Physics/Point.h

@@ -50,10 +50,10 @@ template<UnsignedInt dimensions> class MAGNUM_PHYSICS_EXPORT Point {
          *
          * Creates point at origin.
          */
-        inline constexpr explicit Point() {}
+        inline constexpr /*implicit*/ Point() {}
 
         /** @brief Constructor */
-        inline constexpr explicit Point(const typename DimensionTraits<dimensions>::VectorType& position): _position(position) {}
+        inline constexpr /*implicit*/ Point(const typename DimensionTraits<dimensions>::VectorType& position): _position(position) {}
 
         /** @brief Transformed shape */
         Point<dimensions> transformed(const typename DimensionTraits<dimensions>::MatrixType& matrix) const;

src/Physics/Sphere.h

@@ -54,10 +54,10 @@ template<UnsignedInt dimensions> class MAGNUM_PHYSICS_EXPORT Sphere {
          *
          * Creates zero-sized sphere at origin.
          */
-        inline constexpr explicit Sphere(): _radius(0.0f) {}
+        inline constexpr /*implicit*/ Sphere(): _radius(0.0f) {}
 
         /** @brief Constructor */
-        inline constexpr explicit Sphere(const typename DimensionTraits<dimensions>::VectorType& position, Float radius): _position(position), _radius(radius) {}
+        inline constexpr /*implicit*/ Sphere(const typename DimensionTraits<dimensions>::VectorType& position, Float radius): _position(position), _radius(radius) {}
 
         /** @brief Transformed shape */
         Sphere<dimensions> transformed(const typename DimensionTraits<dimensions>::MatrixType& matrix) const;