[cleanup] Remove check and fallback code for std::conditional.

cmake/modules/CheckCXX11Features.cmake

@@ -13,7 +13,6 @@
 # HAVE_VARIADIC_TEMPLATES          True if variadic templates are supprt
 # HAVE_VARIADIC_CONSTRUCTOR_SFINAE True if variadic constructor sfinae is supported
 # HAVE_RVALUE_REFERENCES           True if rvalue references are supported
-# HAVE_STD_CONDITIONAL             True if std::conditional is supported
 # HAVE_CONSTEXPR                   True if constexpr is supported
 # HAVE_KEYWORD_FINAL               True if final is supported.
 
@@ -282,16 +281,6 @@ check_cxx_source_compiles("
 " HAVE_RVALUE_REFERENCES
 )
 
-# std::conditional
-check_cxx_source_compiles("
-  #include <type_traits>
-
-  int main(void){
-      return std::conditional<true,std::integral_constant<int,0>,void>::type::value;
-  }
-" HAVE_STD_CONDITIONAL
-)
-
 # constexpr
 check_cxx_source_compiles("
   constexpr int foo()

config.h.cmake

@@ -105,9 +105,6 @@
 /* Define to 1 if you have the <type_traits> header file. */
 #cmakedefine HAVE_TYPE_TRAITS 1
 
-/* Define to 1 if you have the <type_traits> header file. */
-#cmakedefine HAVE_STD_CONDITIONAL 1
-
 /* Define to 1 if the MPI2 Standard is supported */
 #cmakedefine MPI_2 1
 

dune/common/typetraits.hh

@@ -373,44 +373,9 @@ namespace Dune
   };
 #endif
 
-#if DOXYGEN || !HAVE_STD_CONDITIONAL
-
-   /**
-   * @brief Select a type based on a condition.
-   *
-   * If template parameter first is true T1 is selected
-   * otherwise T2 will be selected.
-   * The selected type is accessible through the typedef
-   * type.
-   *
-   * \note If available, this uses C++11 std::conditional, otherwise it provides
-   *       a reimplementation.
-   */
-  template<bool first, class T1, class T2>
-  struct conditional
-  {
-    /**
-     * @brief The selected type
-     *
-     * if first is true this will be type T1 and
-     * T2 otherwise
-     */
-    typedef T1 type;
-  };
-
-  template<class T1, class T2>
-  struct conditional<false,T1,T2>
-  {
-    typedef T2 type;
-  };
-
-#else // DOXYGEN || !HAVE_STD_CONDITIONAL
-
   // pull in default implementation
   using std::conditional;
 
-#endif // DOXYGEN || !HAVE_STD_CONDITIONAL
-
   ////////////////////////////////////////////////////////////////////////
   //
   // integral_constant (C++0x 20.7.3 "Helper classes")

m4/CMakeLists.txt

@@ -13,7 +13,6 @@ install(PROGRAMS
         cxx0x_variadic.m4
         cxx0x_variadic_constructor_sfinae.m4
         cxx11_constexpr.m4
-        cxx11_conditional.m4
         cxx11_final.m4
         dune.m4
         dune_all.m4

m4/Makefile.am

@@ -15,7 +15,6 @@ ALLM4S = 					\
 	cxx0x_nullptr.m4			\
 	cxx0x_variadic.m4			\
 	cxx0x_variadic_constructor_sfinae.m4    \
-	cxx11_conditional.m4			\
 	cxx11_constexpr.m4			\
 	cxx11_final.m4				\
 	dune.m4					\

m4/cxx11_conditional.m4

-# tests for C++11 conditional support
-# the associated macro is called HAVE_STD_CONDITIONAL
-
-AC_DEFUN([CXX11_CONDITIONAL_CHECK],[
-  AC_CACHE_CHECK([for C++11 std::conditional], dune_cv_cxx11_conditional_support, [
-    AC_REQUIRE([AC_PROG_CXX])
-    AC_REQUIRE([GXX0X])
-    AC_LANG_PUSH([C++])
-    AC_RUN_IFELSE([
-      AC_LANG_PROGRAM([
-
-        #include <type_traits>
-
-        ],
-        [
-          return std::conditional<true,std::integral_constant<int,0>,void>::type::value;
-        ])],
-      dune_cv_cxx11_conditional_support=yes,
-      dune_cv_cxx11_conditional_support=no)
-    AC_LANG_POP
-  ])
-  if test "x$dune_cv_cxx11_conditional_support" = xyes; then
-    AC_DEFINE(HAVE_STD_CONDITIONAL, 1, [Define to 1 if C++11 std::conditional is supported])
-  fi
-])

m4/dune_common.m4

@@ -23,7 +23,6 @@ AC_DEFUN([DUNE_COMMON_CHECKS],
   AC_REQUIRE([SHARED_PTR])
   AC_REQUIRE([VARIADIC_TEMPLATES_CHECK])
   AC_REQUIRE([RVALUE_REFERENCES_CHECK])
-  AC_REQUIRE([CXX11_CONDITIONAL_CHECK])
   AC_REQUIRE([CXX11_CONSTEXPR_CHECK])
   AC_REQUIRE([DUNE_BOOST_BASE])
   AC_REQUIRE([MAKE_SHARED])