Communicate FieldPerp consistently with other Fields

- Add `Field::field_type()` virtual method
- Removes `Mesh::communicate(FieldPerp&)` overload

Author: ZedThree

include/bout/field.hxx

@@ -6,7 +6,7 @@
  * Copyright 2010 B.D.Dudson, S.Farley, M.V.Umansky, X.Q.Xu
  *
  * Contact: Ben Dudson, bd512@york.ac.uk
- * 
+ *
  * This file is part of BOUT++.
  *
  * BOUT++ is free software: you can redistribute it and/or modify
@@ -30,6 +30,7 @@ class Field;
 #define FIELD_H
 
 #include <cmath>
+#include <cstdint>
 #include <cstdio>
 #include <optional>
 #include <string>
@@ -120,6 +121,11 @@ public:
   /// Get the total number of points
   virtual int size() const = 0;
 
+  /// Enum to distinguish the different kinds of Fields
+  enum class FieldType : std::uint8_t { field3d, field2d, fieldperp };
+  /// Is this an instance of `Field3D`, `Field2D`, or `FieldPerp`?
+  virtual FieldType field_type() const = 0;
+
   friend void swap(Field& first, Field& second) noexcept {
     using std::swap;
     swap(static_cast<FieldData&>(first), static_cast<FieldData&>(second));

include/bout/field2d.hxx

@@ -252,6 +252,7 @@ public:
   // FieldData virtual functions
 
   bool is3D() const override { return false; }
+  FieldType field_type() const override { return FieldType::field2d; }
 
 #if CHECK > 0
   void doneComms() override { bndry_xin = bndry_xout = bndry_yup = bndry_ydown = true; }

include/bout/field3d.hxx

@@ -2,7 +2,7 @@
  * Copyright 2010 B.D.Dudson, S.Farley, M.V.Umansky, X.Q.Xu
  *
  * Contact: Ben Dudson, bd512@york.ac.uk
- * 
+ *
  * This file is part of BOUT++.
  *
  * BOUT++ is free software: you can redistribute it and/or modify
@@ -361,7 +361,7 @@ public:
    * Direct access to the underlying data array
    *
    * If CHECK > 2 then bounds checking is performed
-   * 
+   *
    * If CHECK <= 2 then no checks are performed, to
    * allow inlining and optimisation of inner loops
    */
@@ -474,6 +474,7 @@ public:
 
   // FieldData virtual functions
   bool is3D() const override { return true; }
+  FieldType field_type() const override { return FieldType::field3d; }
 
 #if CHECK > 0
   void doneComms() override { bndry_xin = bndry_xout = bndry_yup = bndry_ydown = true; }

include/bout/fieldgroup.hxx

@@ -1,34 +1,33 @@
 #ifndef BOUT_FIELDGROUP_H
 #define BOUT_FIELDGROUP_H
 
-#include "bout/field_data.hxx"
-#include <bout/field3d.hxx>
-
+#include <bout/traits.hxx>
 #include <bout/vector2d.hxx>
 #include <bout/vector3d.hxx>
 
 #include <vector>
 
-#include <algorithm>
+class Field2D;
+class Field3D;
+class FieldPerp;
+class Field;
 
 /// Group together fields for easier communication
 ///
-/// Note: The FieldData class is used as a base class,
-/// which is inherited by Field2D, Field3D, Vector2D and Vector3D
-/// however Vector2D and Vector3D are stored by reference to their
-/// components (x,y,z) as Field2D or Field3D objects.
+/// Note: The `Field` class is used as a base class,
+/// which is inherited by `Field2D`, `Field3D`, `FieldPerp`;
+/// however `Vector2D` and `Vector3D` are stored by reference to their
+/// components ``(x, y, z)`` as `Field2D` or `Field3D` objects.
 class FieldGroup {
 public:
   FieldGroup() = default;
   FieldGroup(const FieldGroup& other) = default;
   FieldGroup(FieldGroup&& other) = default;
   FieldGroup& operator=(const FieldGroup& other) = default;
   FieldGroup& operator=(FieldGroup&& other) = default;
+  ~FieldGroup() = default;
 
-  /// Constructor with a single FieldData \p f
-  FieldGroup(FieldData& f) { fvec.push_back(&f); }
-
-  /// Constructor with a single Field3D \p f
+  FieldGroup(Field& f) { fvec.push_back(&f); }
   FieldGroup(Field3D& f) {
     fvec.push_back(&f);
     f3vec.push_back(&f);
@@ -56,7 +55,7 @@ public:
   }
 
   /// Variadic constructor. Allows an arbitrary number of
-  /// FieldData arguments
+  /// Field arguments
   ///
   /// The explicit keyword prevents FieldGroup being constructed with arbitrary
   /// types. In particular arguments to add() cannot be implicitly converted
@@ -78,12 +77,12 @@ public:
     return *this;
   }
 
-  /// Add a FieldData \p f to the group.
+  /// Add a Field \p f to the group.
   ///
   /// A pointer to this field will be stored internally,
   /// so the lifetime of this variable should be longer
   /// than the lifetime of this group.
-  void add(FieldData& f) { fvec.push_back(&f); }
+  void add(Field& f) { fvec.push_back(&f); }
 
   // Add a 3D field \p f, which goes into both vectors.
   //
@@ -121,18 +120,8 @@ public:
   }
 
   /// Add multiple fields to this group
-  ///
-  /// This is a variadic template which allows Field3D objects to be
-  /// treated as a special case. An arbitrary number of fields can be
-  /// added.
-  template <typename... Ts>
-  void add(FieldData& t, Ts&... ts) {
-    add(t);     // Add the first using functions above
-    add(ts...); // Add the rest
-  }
-
   template <typename... Ts>
-  void add(Field3D& t, Ts&... ts) {
+  void add(Field& t, Ts&... ts) {
     add(t);     // Add the first using functions above
     add(ts...); // Add the rest
   }
@@ -165,16 +154,14 @@ public:
   }
 
   /// Iteration over all fields
-  using iterator = std::vector<FieldData*>::iterator;
-  iterator begin() { return fvec.begin(); }
-  iterator end() { return fvec.end(); }
+  auto begin() { return fvec.begin(); }
+  auto end() { return fvec.end(); }
 
   /// Const iteration over all fields
-  using const_iterator = std::vector<FieldData*>::const_iterator;
-  const_iterator begin() const { return fvec.begin(); }
-  const_iterator end() const { return fvec.end(); }
+  auto begin() const { return fvec.cbegin(); }
+  auto end() const { return fvec.cend(); }
 
-  const std::vector<FieldData*>& get() const { return fvec; }
+  const std::vector<Field*>& get() const { return fvec; }
 
   /// Iteration over 3D fields
   const std::vector<Field3D*>& field3d() const { return f3vec; }
@@ -183,8 +170,8 @@ public:
   void makeUnique();
 
 private:
-  std::vector<FieldData*> fvec; // Vector of fields
-  std::vector<Field3D*> f3vec;  // Vector of 3D fields
+  std::vector<Field*> fvec;    // Vector of fields
+  std::vector<Field3D*> f3vec; // Vector of 3D fields
 };
 
 /// Combine two FieldGroups

include/bout/fieldperp.hxx

@@ -5,7 +5,7 @@
  * Copyright 2010 B.D.Dudson, S.Farley, M.V.Umansky, X.Q.Xu
  *
  * Contact: Ben Dudson, bd512@york.ac.uk
- * 
+ *
  * This file is part of BOUT++.
  *
  * BOUT++ is free software: you can redistribute it and/or modify
@@ -45,8 +45,8 @@ class Field3D; // #include "bout/field3d.hxx"
 
 /*!
  * Represents a 2D field perpendicular to the magnetic field
- * at a particular index in Y, which only varies in X-Z. 
- * 
+ * at a particular index in Y, which only varies in X-Z.
+ *
  * Primarily used inside field solvers
  */
 class FieldPerp : public Field {
@@ -205,7 +205,7 @@ public:
 
   /*!
    * Access to the underlying data array at a given x,z index
-   * 
+   *
    * If CHECK > 2 then bounds checking is performed, otherwise
    * no checks are performed
    */
@@ -241,9 +241,9 @@ public:
   }
 
   /*!
-   * Access to the underlying data array. (X,Y,Z) indices for consistency with 
+   * Access to the underlying data array. (X,Y,Z) indices for consistency with
    * other field types
-   * 
+   *
    */
   BoutReal& operator()(int jx, int UNUSED(jy), int jz) { return (*this)(jx, jz); }
 
@@ -252,7 +252,7 @@ public:
   }
 
   /*!
-   * Addition, modifying in-place. 
+   * Addition, modifying in-place.
    * This loops over the entire domain, including guard/boundary cells
    */
   FieldPerp& operator+=(const FieldPerp& rhs);
@@ -261,7 +261,7 @@ public:
   FieldPerp& operator+=(BoutReal rhs);
 
   /*!
-   * Subtraction, modifying in place. 
+   * Subtraction, modifying in place.
    * This loops over the entire domain, including guard/boundary cells
    */
   FieldPerp& operator-=(const FieldPerp& rhs);
@@ -270,7 +270,7 @@ public:
   FieldPerp& operator-=(BoutReal rhs);
 
   /*!
-   * Multiplication, modifying in place. 
+   * Multiplication, modifying in place.
    * This loops over the entire domain, including guard/boundary cells
    */
   FieldPerp& operator*=(const FieldPerp& rhs);
@@ -279,7 +279,7 @@ public:
   FieldPerp& operator*=(BoutReal rhs);
 
   /*!
-   * Division, modifying in place. 
+   * Division, modifying in place.
    * This loops over the entire domain, including guard/boundary cells
    */
   FieldPerp& operator/=(const FieldPerp& rhs);
@@ -301,6 +301,7 @@ public:
   int getNz() const override { return nz; };
 
   bool is3D() const override { return false; }
+  FieldType field_type() const override { return FieldType::fieldperp; }
 
   friend void swap(FieldPerp& first, FieldPerp& second) noexcept;
 

include/bout/mesh.hxx

@@ -3,15 +3,15 @@
  *
  * Interface for mesh classes. Contains standard variables and useful
  * routines.
- * 
+ *
  * Changelog
  * =========
  *
  * 2014-12 Ben Dudson <bd512@york.ac.uk>
  *     * Removing coordinate system into separate
  *       Coordinates class
  *     * Adding index derivative functions from derivs.cxx
- * 
+ *
  * 2010-06 Ben Dudson, Sean Farley
  *     * Initial version, adapted from GridData class
  *     * Incorporates code from topology.cpp and Communicator
@@ -20,7 +20,7 @@
  * Copyright 2010-2025 BOUT++ contributors
  *
  * Contact: Ben Dudson, dudson2@llnl.gov
- * 
+ *
  * This file is part of BOUT++.
  *
  * BOUT++ is free software: you can redistribute it and/or modify
@@ -65,6 +65,7 @@ class Mesh;
 #include <optional>
 #include <set>
 #include <string>
+#include <vector>
 
 class BoundaryRegion;
 class BoundaryRegionPar;
@@ -301,11 +302,6 @@ public:
   /// @param g  The group of fields to communicate. Guard cells will be modified
   void communicateYZ(FieldGroup& g);
 
-  /*!
-   * Communicate an X-Z field
-   */
-  virtual void communicate(FieldPerp& f);
-
   /*!
    * Send a list of FieldData objects
    * Packs arguments into a FieldGroup and passes
@@ -815,8 +811,8 @@ protected:
   const std::vector<int> readInts(const std::string& name, int n);
 
   /// Calculates the size of a message for a given x and y range
-  int msg_len(const std::vector<FieldData*>& var_list, int xge, int xlt, int yge,
-              int ylt);
+  int msg_len(const std::vector<Field*>& var_list, int xge, int xlt, int yge,
+              int ylt) const;
 
   /// Initialise derivatives
   void derivs_init(Options* options);