[wpimath] Fix Eigen rule-of-three violations (#2707)

This avoids deprecated-copy warnings on recent clang and GCC compilers.

Applied from https://gitlab.com/libeigen/eigen/-/merge_requests/29/diffs

wpimath/src/main/native/eigeninclude/Eigen/src/Core/ArrayBase.h

@@ -153,8 +153,8 @@ template<typename Derived> class ArrayBase
 //     inline void evalTo(Dest& dst) const { dst = matrix(); }
 
   protected:
-    EIGEN_DEVICE_FUNC
-    ArrayBase() : Base() {}
+    EIGEN_DEFAULT_COPY_CONSTRUCTOR(ArrayBase)
+    EIGEN_DEFAULT_EMPTY_CONSTRUCTOR_AND_DESTRUCTOR(ArrayBase)
 
   private:
     explicit ArrayBase(Index);

wpimath/src/main/native/eigeninclude/Eigen/src/Core/CwiseUnaryView.h

@@ -121,6 +121,8 @@ class CwiseUnaryViewImpl<ViewOp,MatrixType,Dense>
     {
       return derived().nestedExpression().outerStride() * sizeof(typename internal::traits<MatrixType>::Scalar) / sizeof(Scalar);
     }
+  protected:
+    EIGEN_DEFAULT_EMPTY_CONSTRUCTOR_AND_DESTRUCTOR(CwiseUnaryViewImpl)
 };
 
 } // end namespace Eigen

wpimath/src/main/native/eigeninclude/Eigen/src/Core/DenseBase.h

@@ -587,11 +587,12 @@ template<typename Derived> class DenseBase
     }
 
   protected:
+    EIGEN_DEFAULT_COPY_CONSTRUCTOR(DenseBase)
     /** Default constructor. Do nothing. */
     EIGEN_DEVICE_FUNC DenseBase()
     {
       /* Just checks for self-consistency of the flags.
-       * Only do it when debugging Eigen, as this borders on paranoiac and could slow compilation down
+       * Only do it when debugging Eigen, as this borders on paranoia and could slow compilation down
        */
 #ifdef EIGEN_INTERNAL_DEBUGGING
       EIGEN_STATIC_ASSERT((EIGEN_IMPLIES(MaxRowsAtCompileTime==1 && MaxColsAtCompileTime!=1, int(IsRowMajor))

wpimath/src/main/native/eigeninclude/Eigen/src/Core/MapBase.h

@@ -182,6 +182,8 @@ template<typename Derived> class MapBase<Derived, ReadOnlyAccessors>
     #endif
 
   protected:
+    EIGEN_DEFAULT_COPY_CONSTRUCTOR(MapBase)
+    EIGEN_DEFAULT_EMPTY_CONSTRUCTOR_AND_DESTRUCTOR(MapBase)
 
     template<typename T>
     EIGEN_DEVICE_FUNC
@@ -294,6 +296,9 @@ template<typename Derived> class MapBase<Derived, WriteAccessors>
     // In theory we could simply refer to Base:Base::operator=, but MSVC does not like Base::Base,
     // see bugs 821 and 920.
     using ReadOnlyMapBase::Base::operator=;
+  protected:
+    EIGEN_DEFAULT_COPY_CONSTRUCTOR(MapBase)
+    EIGEN_DEFAULT_EMPTY_CONSTRUCTOR_AND_DESTRUCTOR(MapBase)
 };
 
 #undef EIGEN_STATIC_ASSERT_INDEX_BASED_ACCESS

wpimath/src/main/native/eigeninclude/Eigen/src/Core/MatrixBase.h

@@ -464,7 +464,8 @@ template<typename Derived> class MatrixBase
     EIGEN_MATRIX_FUNCTION_1(MatrixComplexPowerReturnValue, pow, power to \c p, const std::complex<RealScalar>& p)
 
   protected:
-    EIGEN_DEVICE_FUNC MatrixBase() : Base() {}
+    EIGEN_DEFAULT_COPY_CONSTRUCTOR(MatrixBase)
+    EIGEN_DEFAULT_EMPTY_CONSTRUCTOR_AND_DESTRUCTOR(MatrixBase)
 
   private:
     EIGEN_DEVICE_FUNC explicit MatrixBase(int);

wpimath/src/main/native/eigeninclude/Eigen/src/Core/Transpose.h

@@ -146,6 +146,8 @@ template<typename MatrixType> class TransposeImpl<MatrixType,Dense>
     {
       return derived().nestedExpression().coeffRef(index);
     }
+  protected:
+    EIGEN_DEFAULT_EMPTY_CONSTRUCTOR_AND_DESTRUCTOR(TransposeImpl)
 };
 
 /** \returns an expression of the transpose of *this.

wpimath/src/main/native/eigeninclude/Eigen/src/Core/TriangularMatrix.h

@@ -217,9 +217,7 @@ template<typename _MatrixType, unsigned int _Mode> class TriangularView
     explicit inline TriangularView(MatrixType& matrix) : m_matrix(matrix)
     {}
     
-    using Base::operator=;
-    TriangularView& operator=(const TriangularView &other)
-    { return Base::operator=(other); }
+    EIGEN_INHERIT_ASSIGNMENT_OPERATORS(TriangularView)
 
     /** \copydoc EigenBase::rows() */
     EIGEN_DEVICE_FUNC
@@ -544,6 +542,10 @@ template<typename _MatrixType, unsigned int _Mode> class TriangularViewImpl<_Mat
     template<typename ProductType>
     EIGEN_DEVICE_FUNC
     EIGEN_STRONG_INLINE TriangularViewType& _assignProduct(const ProductType& prod, const Scalar& alpha, bool beta);
+  protected:
+    EIGEN_DEFAULT_COPY_CONSTRUCTOR(TriangularViewImpl)
+    EIGEN_DEFAULT_EMPTY_CONSTRUCTOR_AND_DESTRUCTOR(TriangularViewImpl)
+
 };
 
 /***************************************************************************

wpimath/src/main/native/eigeninclude/Eigen/src/Core/util/Macros.h

@@ -835,11 +835,44 @@ namespace Eigen {
 #endif
 
 
+/**
+ * \internal
+ * \brief Macro to explicitly define the default copy constructor.
+ * This is necessary, because the implicit definition is deprecated if the copy-assignment is overridden.
+ */
+#if EIGEN_HAS_CXX11
+#define EIGEN_DEFAULT_COPY_CONSTRUCTOR(CLASS) EIGEN_DEVICE_FUNC CLASS(const CLASS&) = default;
+#else
+#define EIGEN_DEFAULT_COPY_CONSTRUCTOR(CLASS)
+#endif
+
+
 /** \internal
  * \brief Macro to manually inherit assignment operators.
  * This is necessary, because the implicitly defined assignment operator gets deleted when a custom operator= is defined.
+ * With C++11 or later this also default-implements the copy-constructor
  */
-#define EIGEN_INHERIT_ASSIGNMENT_OPERATORS(Derived) EIGEN_INHERIT_ASSIGNMENT_EQUAL_OPERATOR(Derived)
+#define EIGEN_INHERIT_ASSIGNMENT_OPERATORS(Derived)  \
+    EIGEN_INHERIT_ASSIGNMENT_EQUAL_OPERATOR(Derived) \
+    EIGEN_DEFAULT_COPY_CONSTRUCTOR(Derived)
+
+/** \internal
+ * \brief Macro to manually define default constructors and destructors.
+ * This is necessary when the copy constructor is re-defined.
+ * For empty helper classes this should usually be protected, to avoid accidentally creating empty objects.
+ *
+ * Hiding the default destructor lead to problems in C++03 mode together with boost::multiprecision
+ */
+#if EIGEN_HAS_CXX11
+#define EIGEN_DEFAULT_EMPTY_CONSTRUCTOR_AND_DESTRUCTOR(Derived)  \
+    EIGEN_DEVICE_FUNC Derived() = default; \
+    EIGEN_DEVICE_FUNC ~Derived() = default;
+#else
+#define EIGEN_DEFAULT_EMPTY_CONSTRUCTOR_AND_DESTRUCTOR(Derived)  \
+    EIGEN_DEVICE_FUNC Derived() {}; \
+    /* EIGEN_DEVICE_FUNC ~Derived() {}; */
+#endif
+
 
 /**
 * Just a side note. Commenting within defines works only by documenting

wpimath/src/main/native/eigeninclude/Eigen/src/Core/util/XprHelper.h

@@ -90,6 +90,9 @@ class no_assignment_operator
 {
   private:
     no_assignment_operator& operator=(const no_assignment_operator&);
+  protected:
+    EIGEN_DEFAULT_COPY_CONSTRUCTOR(no_assignment_operator)
+    EIGEN_DEFAULT_EMPTY_CONSTRUCTOR_AND_DESTRUCTOR(no_assignment_operator)
 };
 
 /** \internal return the index type with the largest number of bits */