diff -r 224d3781b00b -r d886e4b131e6 lemon/tolerance.h
--- a/lemon/tolerance.h	Tue May 09 09:21:48 2006 +0000
+++ b/lemon/tolerance.h	Tue May 09 09:23:39 2006 +0000
@@ -105,7 +105,7 @@
     Tolerance(float e) : _epsilon(e) {}
 
     ///Return the epsilon value.
-    Value epsilon() {return _epsilon;}
+    Value epsilon() const {return _epsilon;}
     ///Set the epsilon value.
     void epsilon(Value e) {_epsilon=e;}
 
@@ -120,15 +120,15 @@
     ///@{
 
     ///Returns \c true if \c a is \e surely strictly less than \c b
-    bool less(Value a,Value b) {return a+_epsilon<b;}
+    bool less(Value a,Value b) const {return a+_epsilon<b;}
     ///Returns \c true if \c a is \e surely different from \c b
-    bool different(Value a,Value b) { return less(a,b)||less(b,a); }
+    bool different(Value a,Value b) const { return less(a,b)||less(b,a); }
     ///Returns \c true if \c a is \e surely positive
-    bool positive(Value a) { return _epsilon<a; }
+    bool positive(Value a) const { return _epsilon<a; }
     ///Returns \c true if \c a is \e surely negative
-    bool negative(Value a) { return -_epsilon>a; }
+    bool negative(Value a) const { return -_epsilon>a; }
     ///Returns \c true if \c a is \e surely non-zero
-    Value nonZero(Value a) { return positive(a)||negative(a); };
+    bool nonZero(Value a) const { return positive(a)||negative(a); };
 
     ///@}
 
@@ -156,7 +156,7 @@
     Tolerance(double e) : _epsilon(e) {}
 
     ///Return the epsilon value.
-    Value epsilon() {return _epsilon;}
+    Value epsilon() const {return _epsilon;}
     ///Set the epsilon value.
     void epsilon(Value e) {_epsilon=e;}
 
@@ -171,15 +171,15 @@
     ///@{
 
     ///Returns \c true if \c a is \e surely strictly less than \c b
-    bool less(Value a,Value b) {return a+_epsilon<b;}
+    bool less(Value a,Value b) const {return a+_epsilon<b;}
     ///Returns \c true if \c a is \e surely different from \c b
-    bool different(Value a,Value b) { return less(a,b)||less(b,a); }
+    bool different(Value a,Value b) const { return less(a,b)||less(b,a); }
     ///Returns \c true if \c a is \e surely positive
-    bool positive(Value a) { return _epsilon<a; }
+    bool positive(Value a) const { return _epsilon<a; }
     ///Returns \c true if \c a is \e surely negative
-    bool negative(Value a) { return -_epsilon>a; }
+    bool negative(Value a) const { return -_epsilon>a; }
     ///Returns \c true if \c a is \e surely non-zero
-    Value nonZero(Value a) { return positive(a)||negative(a); };
+    bool nonZero(Value a) const { return positive(a)||negative(a); };
 
     ///@}
 
@@ -207,7 +207,7 @@
     Tolerance(long double e) : _epsilon(e) {}
 
     ///Return the epsilon value.
-    Value epsilon() {return _epsilon;}
+    Value epsilon() const {return _epsilon;}
     ///Set the epsilon value.
     void epsilon(Value e) {_epsilon=e;}
 
@@ -222,15 +222,15 @@
     ///@{
 
     ///Returns \c true if \c a is \e surely strictly less than \c b
-    bool less(Value a,Value b) {return a+_epsilon<b;}
+    bool less(Value a,Value b) const {return a+_epsilon<b;}
     ///Returns \c true if \c a is \e surely different from \c b
-    bool different(Value a,Value b) { return less(a,b)||less(b,a); }
+    bool different(Value a,Value b) const { return less(a,b)||less(b,a); }
     ///Returns \c true if \c a is \e surely positive
-    bool positive(Value a) { return _epsilon<a; }
+    bool positive(Value a) const { return _epsilon<a; }
     ///Returns \c true if \c a is \e surely negative
-    bool negative(Value a) { return -_epsilon>a; }
+    bool negative(Value a) const { return -_epsilon>a; }
     ///Returns \c true if \c a is \e surely non-zero
-    Value nonZero(Value a) { return positive(a)||negative(a); };
+    bool nonZero(Value a) const { return positive(a)||negative(a); };
 
     ///@}
 
@@ -263,7 +263,7 @@
     ///Returns \c true if \c a is \e surely negative
     static bool negative(Value a) { return 0>a; }
     ///Returns \c true if \c a is \e surely non-zero
-    static Value nonZero(Value a) { return a!=0;};
+    static bool nonZero(Value a) { return a!=0; };
 
     ///@}
 
@@ -299,7 +299,7 @@
     ///Returns \c true if \c a is \e surely negative
     static bool negative(Value a) { return 0>a; }
     ///Returns \c true if \c a is \e surely non-zero
-    static Value nonZero(Value a) { return a!=0;};
+    static bool nonZero(Value a) { return a!=0;};
 
     ///@}