diff --git a/lemon/lgf_reader.h b/lemon/lgf_reader.h
--- a/lemon/lgf_reader.h
+++ b/lemon/lgf_reader.h
@@ -391,15 +391,37 @@
   template <typename Digraph>
   class DigraphReader;
 
+  /// \brief Return a \ref DigraphReader class
+  ///
+  /// This function just returns a \ref DigraphReader class.
+  /// \relates DigraphReader
   template <typename Digraph>
   DigraphReader<Digraph> digraphReader(Digraph& digraph,
-                                       std::istream& is = std::cin);
-
+                                       std::istream& is = std::cin) {
+    DigraphReader<Digraph> tmp(digraph, is);
+    return tmp;
+  }
+
+  /// \brief Return a \ref DigraphReader class
+  ///
+  /// This function just returns a \ref DigraphReader class.
+  /// \relates DigraphReader
   template <typename Digraph>
-  DigraphReader<Digraph> digraphReader(Digraph& digraph, const std::string& fn);
-
+  DigraphReader<Digraph> digraphReader(Digraph& digraph,
+                                       const std::string& fn) {
+    DigraphReader<Digraph> tmp(digraph, fn);
+    return tmp;
+  }
+
+  /// \brief Return a \ref DigraphReader class
+  ///
+  /// This function just returns a \ref DigraphReader class.
+  /// \relates DigraphReader
   template <typename Digraph>
-  DigraphReader<Digraph> digraphReader(Digraph& digraph, const char *fn);
+  DigraphReader<Digraph> digraphReader(Digraph& digraph, const char* fn) {
+    DigraphReader<Digraph> tmp(digraph, fn);
+    return tmp;
+  }
 
   /// \ingroup lemon_io
   ///
@@ -1189,51 +1211,39 @@
 
   };
 
-  /// \brief Return a \ref DigraphReader class
+  template <typename Graph>
+  class GraphReader;
+
+  /// \brief Return a \ref GraphReader class
   ///
-  /// This function just returns a \ref DigraphReader class.
-  /// \relates DigraphReader
-  template <typename Digraph>
-  DigraphReader<Digraph> digraphReader(Digraph& digraph,
-                                       std::istream& is = std::cin) {
-    DigraphReader<Digraph> tmp(digraph, is);
+  /// This function just returns a \ref GraphReader class.
+  /// \relates GraphReader
+  template <typename Graph>
+  GraphReader<Graph> graphReader(Graph& graph, std::istream& is = std::cin) {
+    GraphReader<Graph> tmp(graph, is);
     return tmp;
   }
 
-  /// \brief Return a \ref DigraphReader class
+  /// \brief Return a \ref GraphReader class
   ///
-  /// This function just returns a \ref DigraphReader class.
-  /// \relates DigraphReader
-  template <typename Digraph>
-  DigraphReader<Digraph> digraphReader(Digraph& digraph,
-                                       const std::string& fn) {
-    DigraphReader<Digraph> tmp(digraph, fn);
+  /// This function just returns a \ref GraphReader class.
+  /// \relates GraphReader
+  template <typename Graph>
+  GraphReader<Graph> graphReader(Graph& graph, const std::string& fn) {
+    GraphReader<Graph> tmp(graph, fn);
     return tmp;
   }
 
-  /// \brief Return a \ref DigraphReader class
+  /// \brief Return a \ref GraphReader class
   ///
-  /// This function just returns a \ref DigraphReader class.
-  /// \relates DigraphReader
-  template <typename Digraph>
-  DigraphReader<Digraph> digraphReader(Digraph& digraph, const char* fn) {
-    DigraphReader<Digraph> tmp(digraph, fn);
+  /// This function just returns a \ref GraphReader class.
+  /// \relates GraphReader
+  template <typename Graph>
+  GraphReader<Graph> graphReader(Graph& graph, const char* fn) {
+    GraphReader<Graph> tmp(graph, fn);
     return tmp;
   }
 
-  template <typename Graph>
-  class GraphReader;
-
-  template <typename Graph>
-  GraphReader<Graph> graphReader(Graph& graph,
-                                 std::istream& is = std::cin);
-
-  template <typename Graph>
-  GraphReader<Graph> graphReader(Graph& graph, const std::string& fn);
-
-  template <typename Graph>
-  GraphReader<Graph> graphReader(Graph& graph, const char *fn);
-
   /// \ingroup lemon_io
   ///
   /// \brief \ref lgf-format "LGF" reader for undirected graphs
@@ -2031,36 +2041,6 @@
 
   };
 
-  /// \brief Return a \ref GraphReader class
-  ///
-  /// This function just returns a \ref GraphReader class.
-  /// \relates GraphReader
-  template <typename Graph>
-  GraphReader<Graph> graphReader(Graph& graph, std::istream& is = std::cin) {
-    GraphReader<Graph> tmp(graph, is);
-    return tmp;
-  }
-
-  /// \brief Return a \ref GraphReader class
-  ///
-  /// This function just returns a \ref GraphReader class.
-  /// \relates GraphReader
-  template <typename Graph>
-  GraphReader<Graph> graphReader(Graph& graph, const std::string& fn) {
-    GraphReader<Graph> tmp(graph, fn);
-    return tmp;
-  }
-
-  /// \brief Return a \ref GraphReader class
-  ///
-  /// This function just returns a \ref GraphReader class.
-  /// \relates GraphReader
-  template <typename Graph>
-  GraphReader<Graph> graphReader(Graph& graph, const char* fn) {
-    GraphReader<Graph> tmp(graph, fn);
-    return tmp;
-  }
-
   class SectionReader;
 
   SectionReader sectionReader(std::istream& is);