From a62ecd918ab6a709047b041732bcd8b066839a92 Mon Sep 17 00:00:00 2001
From: Kai Germaschewski <kai.germaschewski@unh.edu>
Date: Mon, 25 Feb 2019 16:36:38 -0500
Subject: [PATCH] rmvar: specialize Variable<Compound>, VariableCompound is now
 only an alias

---
 source/adios2/ADIOSTypes.h              |  4 ++++
 source/adios2/core/VariableCompound.cpp | 17 ++++++++---------
 source/adios2/core/VariableCompound.h   | 20 +++++++++++++-------
 source/adios2/core/VariableCompound.tcc |  4 ++--
 4 files changed, 27 insertions(+), 18 deletions(-)

diff --git a/source/adios2/ADIOSTypes.h b/source/adios2/ADIOSTypes.h
index 4679e3fe50..d23372cccf 100644
--- a/source/adios2/ADIOSTypes.h
+++ b/source/adios2/ADIOSTypes.h
@@ -137,6 +137,10 @@ using std::uint64_t;
 using cfloat = std::complex<float>;
 using cdouble = std::complex<double>;
 
+// Compound is never actually defined, it's just used to template with, in
+// particular Variable<Compound>.
+class Compound;
+
 // Limit, using uint64_t to make it portable
 constexpr uint64_t MaxU64 = std::numeric_limits<uint64_t>::max();
 constexpr size_t MaxSizeT = std::numeric_limits<size_t>::max();
diff --git a/source/adios2/core/VariableCompound.cpp b/source/adios2/core/VariableCompound.cpp
index 05c5282205..f8b596a105 100644
--- a/source/adios2/core/VariableCompound.cpp
+++ b/source/adios2/core/VariableCompound.cpp
@@ -18,19 +18,18 @@ namespace adios2
 namespace core
 {
 
-VariableCompound::VariableCompound(const std::string &name,
-                                   const size_t structSize, const Dims &shape,
-                                   const Dims &start, const Dims &count,
-                                   const bool constantDims,
-                                   const bool debugMode)
-: VariableBase(name, "compound", structSize, shape, start, count, constantDims,
-               debugMode)
+Variable<Compound>::Variable(const std::string &name, const size_t structSize,
+                             const Dims &shape, const Dims &start,
+                             const Dims &count, const bool constantDims,
+                             const bool debugMode)
+: VariableBase(name, "compound", structSize, shape, start, count,
+               constantDims, debugMode)
 {
 }
 
 #define declare_template_instantiation(T)                                      \
-    template void VariableCompound::InsertMember<T>(const std::string &,       \
-                                                    const size_t);
+    template void Variable<Compound>::InsertMember<T>(const std::string &,     \
+                                                      const size_t);
 ADIOS2_FOREACH_STDTYPE_1ARG(declare_template_instantiation)
 #undef declare_template_instantiation
 
diff --git a/source/adios2/core/VariableCompound.h b/source/adios2/core/VariableCompound.h
index f2be1ad9e9..2b63e7d7ca 100644
--- a/source/adios2/core/VariableCompound.h
+++ b/source/adios2/core/VariableCompound.h
@@ -11,7 +11,9 @@
 #ifndef ADIOS2_CORE_VARIABLECOMPOUND_H_
 #define ADIOS2_CORE_VARIABLECOMPOUND_H_
 
-#include "VariableBase.h"
+// FIXME, VariableCompound is now also an alias for Variable<Compound>, so
+// arguably this should be all merged into Variable.{h,tcc,cpp}
+#include "Variable.h"
 
 #include "adios2/ADIOSMacros.h"
 
@@ -24,7 +26,8 @@ namespace core
  * @param Base (parent) class for template derived (child) class CVariable.
  * Required to put CVariable objects in STL containers.
  */
-class VariableCompound : public VariableBase
+template <>
+class Variable<Compound> : public VariableBase
 {
 
 public:
@@ -41,11 +44,12 @@ class VariableCompound : public VariableBase
     /** vector of primitve element types defining compound struct */
     std::vector<Element> m_Elements;
 
-    VariableCompound(const std::string &name, const size_t structSize,
-                     const Dims &shape, const Dims &start, const Dims &count,
-                     const bool constantDims, const bool debugMode);
+    Variable();
+    Variable(const std::string &name, const size_t structSize,
+             const Dims &shape, const Dims &start, const Dims &count,
+             const bool constantDims, const bool debugMode);
 
-    ~VariableCompound() = default;
+    ~Variable() = default;
 
     /**
      * Inserts an Element into the compound struct definition
@@ -58,11 +62,13 @@ class VariableCompound : public VariableBase
 
 // Explicit declaration of the public template methods
 #define declare_template_instantiation(T)                                      \
-    extern template void VariableCompound::InsertMember<T>(                    \
+    extern template void Variable<Compound>::InsertMember<T>(                  \
         const std::string &, const size_t);
 ADIOS2_FOREACH_STDTYPE_1ARG(declare_template_instantiation)
 #undef declare_template_instantiation
 
+using VariableCompound = Variable<Compound>;
+
 } // end namespace core
 } // end namespace adios2
 
diff --git a/source/adios2/core/VariableCompound.tcc b/source/adios2/core/VariableCompound.tcc
index 62d2ad3559..798244c640 100644
--- a/source/adios2/core/VariableCompound.tcc
+++ b/source/adios2/core/VariableCompound.tcc
@@ -21,8 +21,8 @@ namespace core
 {
 
 template <class T>
-void VariableCompound::InsertMember(const std::string &name,
-                                    const size_t offset)
+void Variable<Compound>::InsertMember(const std::string &name,
+                                      const size_t offset)
 {
     m_Elements.push_back(Element{name, helper::GetType<T>(), offset});
 }