From 01fa2c35f751a49d4be348a68f5493e65e7c3e79 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20P=C3=B6schel?= <franz.poeschel@gmail.com>
Date: Mon, 23 Oct 2023 15:21:21 +0200
Subject: [PATCH] Remove duplication of std::variant definition

---
 include/openPMD/auxiliary/Variant.hpp |  4 +--
 include/openPMD/backend/Attribute.hpp | 42 +--------------------------
 2 files changed, 3 insertions(+), 43 deletions(-)

diff --git a/include/openPMD/auxiliary/Variant.hpp b/include/openPMD/auxiliary/Variant.hpp
index 89190b882e..0c0363fc7c 100644
--- a/include/openPMD/auxiliary/Variant.hpp
+++ b/include/openPMD/auxiliary/Variant.hpp
@@ -35,7 +35,7 @@ namespace auxiliary
      * @tparam T        Varaidic template argument list of datatypes to be
      * stored.
      */
-    template <class T_DTYPES, typename... T>
+    template <class T_DTYPES, typename std_variant>
     class Variant
     {
         static_assert(
@@ -43,7 +43,7 @@ namespace auxiliary
             "Datatypes to Variant must be supplied as enum.");
 
     public:
-        using resource = std::variant<T...>;
+        using resource = std_variant;
         /** Construct a lightweight wrapper around a generic object that
          * indicates the concrete datatype of the specific object stored.
          *
diff --git a/include/openPMD/backend/Attribute.hpp b/include/openPMD/backend/Attribute.hpp
index c34d7c1847..6306bcaaf2 100644
--- a/include/openPMD/backend/Attribute.hpp
+++ b/include/openPMD/backend/Attribute.hpp
@@ -52,47 +52,7 @@ namespace openPMD
  * @note Extending and/or modifying the available formats requires identical
  *       modifications to Datatype.
  */
-class Attribute
-    : public auxiliary::Variant<
-          Datatype,
-          char,
-          unsigned char,
-          signed char,
-          short,
-          int,
-          long,
-          long long,
-          unsigned short,
-          unsigned int,
-          unsigned long,
-          unsigned long long,
-          float,
-          double,
-          long double,
-          std::complex<float>,
-          std::complex<double>,
-          std::complex<long double>,
-          std::string,
-          std::vector<char>,
-          std::vector<short>,
-          std::vector<int>,
-          std::vector<long>,
-          std::vector<long long>,
-          std::vector<unsigned char>,
-          std::vector<unsigned short>,
-          std::vector<unsigned int>,
-          std::vector<unsigned long>,
-          std::vector<unsigned long long>,
-          std::vector<float>,
-          std::vector<double>,
-          std::vector<long double>,
-          std::vector<std::complex<float>>,
-          std::vector<std::complex<double>>,
-          std::vector<std::complex<long double>>,
-          std::vector<signed char>,
-          std::vector<std::string>,
-          std::array<double, 7>,
-          bool>
+class Attribute : public auxiliary::Variant<Datatype, attribute_types>
 {
 public:
     Attribute(resource r) : Variant(std::move(r))