switchless component access

PHAREHUB · Dec 19, 2023 · 78d0536 · 78d0536
1 parent 94fac3e
commit 78d0536
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Showing 2 changed files with 17 additions and 24 deletions.
diff --git a/src/core/data/tensorfield/tensorfield.hpp b/src/core/data/tensorfield/tensorfield.hpp
@@ -20,14 +20,24 @@ template<typename NdArrayImpl, typename PhysicalQuantity, std::size_t rank_ = 1>
 class TensorField
 {
 private:
+    template<std::size_t _rank = rank_>
     constexpr static std::size_t dimFromRank()
     {
-        if constexpr (rank_ == 1) // Vector field
+        if constexpr (_rank == 1) // Vector field
             return 3;
-        else if constexpr (rank_ == 2) // symmetric 3x3 tensor field
+        else if constexpr (_rank == 2) // symmetric 3x3 tensor field
             return 6;
     }
 
+    auto static _get_index_for(Component component)
+    {
+        auto val = static_cast<std::underlying_type_t<Component>>(component);
+        if constexpr (rank == 1)
+            return val;
+        else if constexpr (rank == 2)
+            return val - dimFromRank<1>();
+    }
+
 public:
     TensorField()                                     = delete;
     TensorField(TensorField const& source)            = delete;
@@ -116,24 +126,7 @@ class TensorField
     NO_DISCARD std::string const& name() const { return name_; }
 
 
-    template<typename Arg>
-    NO_DISCARD decltype(auto) static _switcheroo(Component component, Arg& arg)
-    {
-        switch (component)
-        {
-            case Component::X: return arg[0];
-            case Component::Y: return arg[1];
-            case Component::Z: return arg[2];
-
-            case Component::XX: return arg[0];
-            case Component::XY: return arg[1];
-            case Component::XZ: return arg[2];
-            case Component::YY: return arg[3];
-            case Component::YZ: return arg[4];
-            case Component::ZZ: return arg[5];
-        }
-        throw std::runtime_error("Error - TensorField not usable");
-    }
+
 
     void _check() const
     {
@@ -144,7 +137,7 @@ class TensorField
     NO_DISCARD field_type& getComponent(Component component)
     {
         _check();
-        return *_switcheroo(component, components_);
+        return *components_[_get_index_for(component)];
     }
 
 
@@ -153,14 +146,14 @@ class TensorField
     NO_DISCARD field_type const& getComponent(Component component) const
     {
         _check();
-        return *_switcheroo(component, components_);
+        return *components_[_get_index_for(component)];
     }
 
 
 
     NO_DISCARD std::string getComponentName(Component component) const
     {
-        return _switcheroo(component, componentNames_);
+        return componentNames_[_get_index_for(component)];
     }
 
 

diff --git a/src/core/data/vecfield/vecfield_component.hpp b/src/core/data/vecfield/vecfield_component.hpp
@@ -9,7 +9,7 @@ namespace PHARE
 {
 namespace core
 {
-    enum class Component { X, Y, Z, XX, XY, XZ, YY, YZ, ZZ };
+    enum class Component : std::uint16_t { X = 0, Y, Z, XX, XY, XZ, YY, YZ, ZZ };
 
     struct Components
     {