From: Wolfgang Bangerth <bangerth@math.tamu.edu>
Date: Mon, 6 May 2002 07:33:49 +0000 (+0000)
Subject: Detect and work around a bug involving typedefing with template template arguments... 
X-Git-Tag: v8.0.0~18056
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6634b123e52617852df59bf2671a95804481f382;p=dealii.git

Detect and work around a bug involving typedefing with template template arguments in gcc2.95. Previously, we simply checked for the version number of the compiler, but we should get away from this and rather check for compiler features using autoconf, to make the whole thing more portable.


git-svn-id: https://svn.dealii.org/trunk@5805 0785d39b-7218-0410-832d-ea1e28bc413d
---

diff --git a/deal.II/aclocal.m4 b/deal.II/aclocal.m4
index d67f98269d..01679112e8 100644
--- a/deal.II/aclocal.m4
+++ b/deal.II/aclocal.m4
@@ -1771,6 +1771,62 @@ AC_DEFUN(DEAL_II_CHECK_IMPLEMENTED_PURE_FUNCTION_BUG, dnl
 
 
 
+dnl -------------------------------------------------------------
+dnl gcc 2.95 dies on this construct:
+dnl -----------------------------
+dnl template <int dim> struct TT { typedef int type; };
+dnl
+dnl template <template <int> class T> struct X {
+dnl     typedef typename T<1>::type type;
+dnl     void foo (type t);
+dnl };
+dnl
+dnl template <template <int> class T>
+dnl void X<T>::foo (type t) {};
+dnl
+dnl template struct X<TT>;
+dnl -----------------------------
+dnl
+dnl We work around this problem, if we encounter it.
+dnl
+dnl Usage: DEAL_II_CHECK_TEMPLATE_TEMPLATE_TYPEDEF_BUG
+dnl
+dnl -------------------------------------------------------------
+AC_DEFUN(DEAL_II_CHECK_TEMPLATE_TEMPLATE_TYPEDEF_BUG, dnl
+[
+  AC_MSG_CHECKING(for template template typedef bug)
+  AC_LANG(C++)
+  CXXFLAGS="$CXXFLAGSG"
+  AC_TRY_COMPILE(
+    [
+	template <int dim> struct TT { typedef int type; };
+
+	template <template <int> class T> struct X {
+	    typedef typename T<1>::type type;
+	    void foo (type t);
+	};
+
+	template <template <int> class T>
+	void X<T>::foo (type t) {};
+
+	template struct X<TT>;
+    ],
+    [],
+    [
+      AC_MSG_RESULT(no)
+    ],
+    [
+      AC_MSG_RESULT(yes. using workaround)
+      AC_DEFINE(DEAL_II_TEMPLATE_TEMPLATE_TYPEDEF_BUG, 1, 
+                     [Defined if the compiler refuses to allow a typedef
+                      to a template template class template parameter. For
+                      the exact failure mode, look at aclocal.m4 in the
+                      top-level directory.])
+    ])
+])
+
+
+
 
 dnl -------------------------------------------------------------
 dnl gcc2.95 doesn't have the std::iterator class, but the standard
diff --git a/deal.II/configure.in b/deal.II/configure.in
index 7ccc7ac39d..02ccdf5ed6 100644
--- a/deal.II/configure.in
+++ b/deal.II/configure.in
@@ -158,6 +158,7 @@ DEAL_II_CHECK_NAMESP_TEMPL_FRIEND_BUG
 DEAL_II_CHECK_TEMPL_CONST_MEM_PTR_BUG
 DEAL_II_CHECK_CONST_MEM_FUN_PTR_BUG
 DEAL_II_CHECK_IMPLEMENTED_PURE_FUNCTION_BUG
+DEAL_II_CHECK_TEMPLATE_TEMPLATE_TYPEDEF_BUG
 DEAL_II_HAVE_STD_ITERATOR
 DEAL_II_HAVE_STD_STRINGSTREAM
 DEAL_II_HAVE_STD_NUMERIC_LIMITS
diff --git a/deal.II/deal.II/include/grid/intergrid_map.h b/deal.II/deal.II/include/grid/intergrid_map.h
index 4dd9aad348..ad09cd3cc6 100644
--- a/deal.II/deal.II/include/grid/intergrid_map.h
+++ b/deal.II/deal.II/include/grid/intergrid_map.h
@@ -114,9 +114,10 @@ class InterGridMap
 {
   public:
 
-#if (__GNUC__==2) && (__GNUC_MINOR__==95)
+#ifdef DEAL_II_TEMPLATE_TEMPLATE_TYPEDEF
 				     // helper class
-    struct GridClass_dim : public GridClass<dim> {
+    struct GridClass_dim : public GridClass<dim>
+    {
 					 // constructor. will
 					 // not be implemented,
 					 // but suppresses compiler