From 7c07f3149f208fb09ebbff8c53c6e9a8b9458114 Mon Sep 17 00:00:00 2001
From: Alexandre Duret-Lutz <adl@lrde.epita.fr>
Date: Fri, 7 Jan 2005 10:27:17 +0000
Subject: [PATCH] * src/tgbaalgos/ndfs_result.hxx (ndfs_result,
 acss_interface): Conditionally inherit from acss_statistics. *
 src/tgbaalgos/magic.cc, src/tgbaalgos/se05.cc, src/tgbaalgos/tau03.cc,
 src/tgbaalgos/tau03opt.cc: Define Has_Size in all heaps.

---
 ChangeLog                     |  7 +++++++
 src/tgbaalgos/magic.cc        |  8 ++------
 src/tgbaalgos/ndfs_result.hxx | 36 ++++++++++++++++++++++++++++-------
 src/tgbaalgos/se05.cc         |  8 ++------
 src/tgbaalgos/tau03.cc        |  1 +
 src/tgbaalgos/tau03opt.cc     |  1 +
 6 files changed, 42 insertions(+), 19 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 215a2c5a4..ea51b4701 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2005-01-07  Alexandre Duret-Lutz  <adl@src.lip6.fr>
+
+	* src/tgbaalgos/ndfs_result.hxx (ndfs_result, acss_interface):
+	Conditionally inherit from acss_statistics.
+	* src/tgbaalgos/magic.cc, src/tgbaalgos/se05.cc, src/tgbaalgos/tau03.cc,
+	src/tgbaalgos/tau03opt.cc: Define Has_Size in all heaps.
+
 2005-01-06  Denis Poitrenaud  <Denis.Poitrenaud@lip6.fr>
 
 	* src/ltltest/randltl.cc: Include cassert.
diff --git a/src/tgbaalgos/magic.cc b/src/tgbaalgos/magic.cc
index 6f86b0ed8..5115f8ca2 100644
--- a/src/tgbaalgos/magic.cc
+++ b/src/tgbaalgos/magic.cc
@@ -387,6 +387,7 @@ namespace spot
           return (it != h.end());
         }
 
+      enum { Has_Size = 1 };
       int size() const
         {
           return h.size();
@@ -461,12 +462,7 @@ namespace spot
           return color((h[ha%size_] >> ((ha%4)*2)) & 3U) != WHITE;
         }
 
-      int size() const
-        {
-          // this method must return the number of state stored in the heap. Due
-          // to potential conflicts this size cannot be computed.
-          return 0;
-        }
+      enum { Has_Size = 0 };
 
     private:
       size_t size_;
diff --git a/src/tgbaalgos/ndfs_result.hxx b/src/tgbaalgos/ndfs_result.hxx
index f8c543761..6cfd74a70 100644
--- a/src/tgbaalgos/ndfs_result.hxx
+++ b/src/tgbaalgos/ndfs_result.hxx
@@ -61,11 +61,37 @@ namespace spot
 
   typedef std::list<stack_item> stack_type;
 
+  namespace
+  {
+    // The acss_statistics is available only when the heap has a
+    // size() method (which we indicate using n==1).
+
+    template <typename T, int n>
+    struct acss_interface
+    {
+    };
+
+    template <typename T>
+    struct acss_interface<T, 1>
+      : public acss_statistics
+    {
+      int
+      acss_states() const
+      {
+	// all visited states are in the state space search
+	return dynamic_cast<const T*>(this)->h_.size();
+      }
+    };
+
+  }
+
+
   template <typename ndfs_search, typename heap>
   class ndfs_result:
     public emptiness_check_result,
     public ars_statistics,
-    public acss_statistics
+    // Conditionally inherit from acss_statistics.
+    public acss_interface<ndfs_result<ndfs_search, heap>, heap::Has_Size>
   {
   public:
     ndfs_result(const ndfs_search& ms)
@@ -74,12 +100,6 @@ namespace spot
     {
     }
 
-    int acss_states() const
-    {
-      // all visited states are in the state space search
-      return h_.size();
-    }
-
     virtual ~ndfs_result()
     {
     }
@@ -195,6 +215,8 @@ namespace spot
   private:
     const ndfs_search& ms_;
     const heap& h_;
+    template <typename T, int n>
+    friend struct acss_interface;
 
     struct transition {
       const state* source;
diff --git a/src/tgbaalgos/se05.cc b/src/tgbaalgos/se05.cc
index e11371444..9e2a3cc87 100644
--- a/src/tgbaalgos/se05.cc
+++ b/src/tgbaalgos/se05.cc
@@ -445,6 +445,7 @@ namespace spot
           return true;
         }
 
+      enum { Has_Size = 1 };
       int size() const
         {
           return h.size() + hc.size();
@@ -548,12 +549,7 @@ namespace spot
           return color((h[ha%size_] >> ((ha%4)*2)) & 3U) != WHITE;
         }
 
-      int size() const
-        {
-          // this method must return the number of state stored in the heap. Due
-          // to potential conflicts this size cannot be computed.
-          return 0;
-        }
+      enum { Has_Size = 0 };
 
     private:
       size_t size_;
diff --git a/src/tgbaalgos/tau03.cc b/src/tgbaalgos/tau03.cc
index 49d9e5302..b1b9723a6 100644
--- a/src/tgbaalgos/tau03.cc
+++ b/src/tgbaalgos/tau03.cc
@@ -361,6 +361,7 @@ namespace spot
           return (it != h.end());
         }
 
+      enum { Has_Size = 1 };
       int size() const
         {
           return h.size();
diff --git a/src/tgbaalgos/tau03opt.cc b/src/tgbaalgos/tau03opt.cc
index 8f5ccce2a..f8dc61263 100644
--- a/src/tgbaalgos/tau03opt.cc
+++ b/src/tgbaalgos/tau03opt.cc
@@ -481,6 +481,7 @@ namespace spot
           return true;
         }
 
+      enum { Has_Size = 1 };
       int size() const
         {
           return h.size() + hc.size();