eo/src/eoPrintable.h

@@ -0,0 +1,45 @@
+// -*- mode: c++; c-indent-level: 4; c++-member-init-indent: 8; comment-column: 35; -*-
+
+//-----------------------------------------------------------------------------
+// eoPrintable.h
+// (c) GeNeura Team, 1998
+//-----------------------------------------------------------------------------
+
+#ifndef EOPRINTABLE_H
+#define EOPRINTABLE_H
+
+//-----------------------------------------------------------------------------
+
+#include <iostream>  // istream, ostream
+#include <string> // para string
+
+using namespace std;
+
+//-----------------------------------------------------------------------------
+// eoPrintable
+//-----------------------------------------------------------------------------
+/**
+Base class for objects that can print themselves
+(#printOn#). Besides, this file defines the standard output for all the objects; 
+if the objects define printOn there's no need to define #operator <<#.\\
+This functionality was separated from eoObject, since it makes no sense to print
+some objects (for instance, a #eoFactory# or a random number generator.
+ */
+class eoPrintable
+{
+ public:
+  /// Virtual dtor. They are needed in virtual class hierarchies.
+  virtual ~eoPrintable() {}
+  
+  /**
+   * Write object. It's called printOn since it prints the object on a stream.
+   * @param _os A ostream.
+   */
+  virtual void printOn(ostream& _os) const = 0;
+};
+
+//-----------------------------------------------------------------------------
+///Standard output for all objects in the EO hierarchy
+ostream & operator << ( ostream& _os, const eoPrintable& _o );
+
+#endif EOPRINTABLE_H