From 49501047bcab4220c314c59b2ca601ac33c3c0cb Mon Sep 17 00:00:00 2001
From: Wolfgang Bangerth <bangerth@colostate.edu>
Date: Fri, 27 Oct 2017 12:47:38 -0600
Subject: [PATCH] Simplify variadic constructors.

---
 include/deal.II/base/patterns.h | 41 +++++++++++++--------------------
 1 file changed, 16 insertions(+), 25 deletions(-)

diff --git a/include/deal.II/base/patterns.h b/include/deal.II/base/patterns.h
index 7f143c4303..d694d4e1b4 100644
--- a/include/deal.II/base/patterns.h
+++ b/include/deal.II/base/patterns.h
@@ -1254,45 +1254,36 @@ namespace Patterns
 {
   template<class... PatternTypes>
   Tuple::Tuple(const char *separator,
-               const PatternTypes &... ps) :
-    separator(separator)
-  {
-    static_assert(is_base_of_all<PatternBase, PatternTypes...>::value,
-                  "Not all of the input arguments of this function "
-                  "are derived from PatternBase");
-    std::initializer_list<const PatternBase *> pss = { &ps... };
-    for (auto p : pss)
-      patterns.push_back(p->clone());
-  }
+               const PatternTypes &... ps)
+    :
+    // simply forward to the std::string version
+    Tuple (std::string(separator), ps...)
+  {}
 
 
 
   template<class... PatternTypes>
   Tuple::Tuple(const std::string &separator,
-               const PatternTypes &... ps) :
-    separator(separator)
+               const PatternTypes &... ps)
+    :
+    separator (separator)
   {
     static_assert(is_base_of_all<PatternBase, PatternTypes...>::value,
                   "Not all of the input arguments of this function "
                   "are derived from PatternBase");
-    std::initializer_list<const PatternBase *> pss = { &ps... };
-    for (auto p : pss)
-      patterns.push_back(p->clone());
+    auto pattern_pointers = { (static_cast<const PatternBase *>(&ps))... };
+    for (auto p : pattern_pointers)
+      patterns.push_back (p->clone());
   }
 
 
 
   template<class... PatternTypes>
-  Tuple::Tuple(const PatternTypes &... ps) :
-    separator(",")
-  {
-    static_assert(is_base_of_all<PatternBase, PatternTypes...>::value,
-                  "Not all of the input arguments of this function "
-                  "are derived from PatternBase");
-    std::initializer_list<const PatternBase *> pss = { &ps... };
-    for (auto p : pss)
-      patterns.push_back(p->clone());
-  }
+  Tuple::Tuple(const PatternTypes &... ps)
+    :
+    // forward to the version with the separator argument
+    Tuple (std::string(","), ps...)
+  {}
 
 
 
-- 
2.39.5