Adding a partially useful boolean operator function for the ogzfstream

Author: andrewdavidsmith

zlib_wrapper.hpp

@@ -39,21 +39,25 @@ struct igzfstream {
   gzFile fileobj;
 };
 
+igzfstream&
+getline(igzfstream &in, std::string &line);
+
+igzfstream&
+operator>>(igzfstream &in, std::string &line);
+
+
 struct ogzfstream {
   ogzfstream(const std::string filename) :
     fileobj(gzopen(filename.c_str(), "w")) {}
   ~ogzfstream() {gzclose_w(fileobj);}
-  /* eof is not a good error indicator for write */
-  // operator bool() const {return !gzeof(fileobj);}
+
+  /* Below: eof is not a good error indicator for output streams and
+   * we often use this only when checking after opening a file. This
+   * function needs improving */
+  operator bool() const {return fileobj != NULL;}
   gzFile fileobj;
 };
 
-igzfstream&
-getline(igzfstream &in, std::string &line);
-
-igzfstream&
-operator>>(igzfstream &in, std::string &line);
-
 ogzfstream&
 operator<<(ogzfstream &out, const std::string &line);