gzstream: istream constructor should be called first

istream initializes the buffer buf while gzstreambase constructor opens the file and
may set some flags (in case the file can't be opened). If istream is called last
it will overwrite the flags that have been set

algo/lib/gzstream.h

@@ -89,22 +89,22 @@ public:
 // function interface of the zlib. Files are compatible with gzip compression.
 // ----------------------------------------------------------------------------
 
-class igzstream : public gzstreambase, public std::istream {
+class igzstream :  public std::istream, public gzstreambase {
 public:
     igzstream() : std::istream( &buf) {} 
     igzstream( const char* name, int open_mode = std::ios::in)
-        : gzstreambase( name, open_mode), std::istream( &buf) {}  
+      : std::istream( &buf), gzstreambase( name, open_mode) {}
     gzstreambuf* rdbuf() { return gzstreambase::rdbuf(); }
     void open( const char* name, int open_mode = std::ios::in) {
         gzstreambase::open( name, open_mode);
     }
 };
 
-class ogzstream : public gzstreambase, public std::ostream {
+class ogzstream : public std::ostream, public gzstreambase  {
 public:
     ogzstream() : std::ostream( &buf) {}
     ogzstream( const char* name, int mode = std::ios::out)
-        : gzstreambase( name, mode), std::ostream( &buf) {}  
+      : std::ostream( &buf), gzstreambase( name, mode) {}
     gzstreambuf* rdbuf() { return gzstreambase::rdbuf(); }
     void open( const char* name, int open_mode = std::ios::out) {
         gzstreambase::open( name, open_mode);