1.1 --- a/lemon/bits/graph_adaptor_extender.h	Sun Jan 05 22:24:56 2014 +0100
     1.2 +++ b/lemon/bits/graph_adaptor_extender.h	Tue Apr 14 08:39:40 2015 +0200
     1.3 @@ -85,7 +85,7 @@
     1.4  
     1.5      };
     1.6  
     1.7 -    LemonRangeWrapper1<NodeIt, Adaptor> nodes() {
     1.8 +    LemonRangeWrapper1<NodeIt, Adaptor> nodes() const {
     1.9        return LemonRangeWrapper1<NodeIt, Adaptor>(*this);
    1.10      }
    1.11  
    1.12 @@ -111,7 +111,7 @@
    1.13  
    1.14      };
    1.15  
    1.16 -    LemonRangeWrapper1<ArcIt, Adaptor> arcs() {
    1.17 +    LemonRangeWrapper1<ArcIt, Adaptor> arcs() const {
    1.18        return LemonRangeWrapper1<ArcIt, Adaptor>(*this);
    1.19      }
    1.20  
    1.21 @@ -269,7 +269,7 @@
    1.22  
    1.23      };
    1.24  
    1.25 -    LemonRangeWrapper1<NodeIt, Adaptor> nodes() {
    1.26 +    LemonRangeWrapper1<NodeIt, Adaptor> nodes() const {
    1.27        return LemonRangeWrapper1<NodeIt, Adaptor>(*this);
    1.28      }
    1.29  
    1.30 @@ -296,7 +296,7 @@
    1.31  
    1.32      };
    1.33  
    1.34 -    LemonRangeWrapper1<ArcIt, Adaptor> arcs() {
    1.35 +    LemonRangeWrapper1<ArcIt, Adaptor> arcs() const {
    1.36        return LemonRangeWrapper1<ArcIt, Adaptor>(*this);
    1.37      }
    1.38  
    1.39 @@ -378,7 +378,7 @@
    1.40  
    1.41      };
    1.42  
    1.43 -    LemonRangeWrapper1<EdgeIt, Adaptor> edges() {
    1.44 +    LemonRangeWrapper1<EdgeIt, Adaptor> edges() const {
    1.45        return LemonRangeWrapper1<EdgeIt, Adaptor>(*this);
    1.46      }
    1.47