* QR: add a rank() method and improve the accuracy of the rank

* computation
* Array: add a count() method and rename AllAndAny.h file to
  BooleanRedux.h

Eigen/src/Array/BooleanRedux.h

@@ -89,7 +89,7 @@ struct ei_any_unroller<Derived, Dynamic>
   * \sa MatrixBase::any(), Cwise::operator<()
   */
 template<typename Derived>
-inline bool MatrixBase<Derived>::all(void) const
+inline bool MatrixBase<Derived>::all() const
 {
   const bool unroll = SizeAtCompileTime * (CoeffReadCost + NumTraits<Scalar>::AddCost)
                       <= EIGEN_UNROLLING_LIMIT;
@@ -113,7 +113,7 @@ inline bool MatrixBase<Derived>::all(void) const
   * \sa MatrixBase::all()
   */
 template<typename Derived>
-inline bool MatrixBase<Derived>::any(void) const
+inline bool MatrixBase<Derived>::any() const
 {
   const bool unroll = SizeAtCompileTime * (CoeffReadCost + NumTraits<Scalar>::AddCost)
                       <= EIGEN_UNROLLING_LIMIT;
@@ -130,4 +130,16 @@ inline bool MatrixBase<Derived>::any(void) const
   }
 }
 
+/** \array_module
+  * 
+  * \returns the number of coefficients which evaluate to true
+  *
+  * \sa MatrixBase::all(), MatrixBase::any()
+  */
+template<typename Derived>
+inline int MatrixBase<Derived>::count() const
+{
+  return this->cast<bool>().cast<int>().sum();
+}
+
 #endif // EIGEN_ALLANDANY_H

Eigen/src/Array/Functors.h

@@ -200,7 +200,6 @@ template<typename Scalar>
 struct ei_functor_traits<ei_scalar_cube_op<Scalar> >
 { enum { Cost = 2*NumTraits<Scalar>::MulCost, PacketAccess = int(ei_packet_traits<Scalar>::size)>1 }; };
 
-
 // default ei_functor_traits for STL functors:
 
 template<typename T>