From: David Wells <wellsd2@rpi.edu>
Date: Mon, 5 Oct 2015 15:18:05 +0000 (-0400)
Subject: Wrap boost::enable_if_c as std_cxx11::enable_if.
X-Git-Tag: v8.4.0-rc2~338^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a4a9f78840dec8a53e2a245633979212d73b6b1a;p=dealii.git

Wrap boost::enable_if_c as std_cxx11::enable_if.

Note that boost::enable_if is not quite the same thing as std::enable_if
from the C++11 standard library.

This cleans up some of the memory consumption code.
---

diff --git a/include/deal.II/base/memory_consumption.h b/include/deal.II/base/memory_consumption.h
index 58e9fcbb54..20dc2fed48 100644
--- a/include/deal.II/base/memory_consumption.h
+++ b/include/deal.II/base/memory_consumption.h
@@ -22,10 +22,6 @@
 #include <deal.II/base/std_cxx11/type_traits.h>
 #include <deal.II/base/std_cxx11/unique_ptr.h>
 
-// unfortunately, boost::enable_if_c, not boost::enable_if, is equivalent to
-// std::enable_if
-#include <boost/utility/enable_if.hpp>
-
 #include <string>
 #include <complex>
 #include <vector>
@@ -100,7 +96,7 @@ namespace MemoryConsumption
    */
   template <typename T>
   inline
-  typename boost::enable_if_c<std_cxx11::is_fundamental<T>::value, std::size_t>::type
+  typename std_cxx11::enable_if<std_cxx11::is_fundamental<T>::value, std::size_t>::type
   memory_consumption (const T &t);
 
   /**
@@ -111,7 +107,7 @@ namespace MemoryConsumption
    */
   template <typename T>
   inline
-  typename boost::enable_if_c<!(std_cxx11::is_fundamental<T>::value || std_cxx11::is_pointer<T>::value), std::size_t>::type
+  typename std_cxx11::enable_if<!(std_cxx11::is_fundamental<T>::value || std_cxx11::is_pointer<T>::value), std::size_t>::type
   memory_consumption (const T &t);
 
   /**
@@ -248,7 +244,7 @@ namespace MemoryConsumption
 {
   template <typename T>
   inline
-  typename boost::enable_if_c<std_cxx11::is_fundamental<T>::value, std::size_t>::type
+  typename std_cxx11::enable_if<std_cxx11::is_fundamental<T>::value, std::size_t>::type
   memory_consumption(const T &)
   {
     return sizeof(T);
@@ -380,7 +376,7 @@ namespace MemoryConsumption
 
   template <typename T>
   inline
-  typename boost::enable_if_c<!(std_cxx11::is_fundamental<T>::value || std_cxx11::is_pointer<T>::value), std::size_t>::type
+  typename std_cxx11::enable_if<!(std_cxx11::is_fundamental<T>::value || std_cxx11::is_pointer<T>::value), std::size_t>::type
   memory_consumption (const T &t)
   {
     return t.memory_consumption();
diff --git a/include/deal.II/base/std_cxx11/type_traits.h b/include/deal.II/base/std_cxx11/type_traits.h
index 114485d1e9..261f67392e 100644
--- a/include/deal.II/base/std_cxx11/type_traits.h
+++ b/include/deal.II/base/std_cxx11/type_traits.h
@@ -32,12 +32,14 @@ namespace std_cxx11
   using std::is_pointer;
   using std::is_standard_layout;
   using std::is_trivial;
+  using std::enable_if;
 }
 DEAL_II_NAMESPACE_CLOSE
 
 #else
 
 #include <boost/type_traits.hpp>
+#include <boost/core/enable_if.hpp>
 DEAL_II_NAMESPACE_OPEN
 namespace std_cxx11
 {
@@ -45,6 +47,11 @@ namespace std_cxx11
   using boost::is_pod;
   using boost::is_pointer;
 
+  // boost::enable_if_c, *not* boost::enable_if, is equivalent to std::enable_if.
+  template <bool B, class T = void>
+  struct enable_if : public boost::enable_if_c<B, T>
+  {};
+
   // boost does not have is_standard_layout and
   // is_trivial, but those are both a subset of
   // is_pod