svn commit: r355532 - /incubator/stdcxx/trunk/examples/manual/list.cpp

[se...@apache.org]

Author: sebor
Date: Fri Dec  9 08:44:58 2005
New Revision: 355532

URL: http://svn.apache.org/viewcvs?rev=355532&view=rev
Log:
2005-12-09  Martin Sebor  <se...@roguewave.com>

	* list.cpp (operator<<): Added comments.
	(main): Replaced endl with '\n' for efficiency.

Modified:
    incubator/stdcxx/trunk/examples/manual/list.cpp

Modified: incubator/stdcxx/trunk/examples/manual/list.cpp
URL: http://svn.apache.org/viewcvs/incubator/stdcxx/trunk/examples/manual/list.cpp?rev=355532&r1=355531&r2=355532&view=diff
==============================================================================
--- incubator/stdcxx/trunk/examples/manual/list.cpp (original)
+++ incubator/stdcxx/trunk/examples/manual/list.cpp Fri Dec  9 08:44:58 2005
@@ -2,7 +2,7 @@
  *
  * list.cpp - Example program of list class.
  *
- * $Id: //stdlib/dev/examples/stdlib/manual/list.cpp#13 $
+ * $Id$
  *
  ***************************************************************************
  *
@@ -22,7 +22,7 @@
 #include <algorithm>   // for find
 #include <list>        // for list
 #include <string>      // for string
-#include <iostream>    // for cout, endl
+#include <iostream>    // for cout
 
 #include <examples.h>
 
@@ -33,18 +33,28 @@
 // stream out a list of strings
 std::ostream& operator<< (std::ostream &out, const StringList &l)
 {
+    // create a sentry object to guard the stream
     const std::ostream::sentry guard (out);
 
-    for (StringList::const_iterator i = l.begin (); i != l.end (); ++i) {
+    if (guard) {
 
-        const std::streamsize n =
-            out.rdbuf ()->sputn ((*i).data (), (*i).size ());
+        // the guard succeeded in preparing the stream for output
 
-        if (   std::streamsize ((*i).size ()) != n
-            ||    std::ostream::traits_type::to_int_type (' ')
-               != out.rdbuf ()->sputc (' ')) {
-            out.setstate (std::ios::badbit);
-            break;
+        for (StringList::const_iterator i = l.begin (); i != l.end (); ++i) {
+
+            // insert the string into the stream object's buffer
+            const std::streamsize n =
+                out.rdbuf ()->sputn ((*i).data (), (*i).size ());
+
+            // insert the space character into the buffer
+            if (   std::streamsize ((*i).size ()) != n
+                ||    std::ostream::traits_type::to_int_type (' ')
+                   != out.rdbuf ()->sputc (' ')) {
+
+                // set badbit if either operation failed
+                out.setstate (std::ios::badbit);
+                break;
+            }
         }
     }
 
@@ -57,17 +67,17 @@
     // Create a list of critters.
     StringList critters;
 
-    // Insert several critters.
+    // Insert a few critters.
     critters.insert (critters.begin (), "antelope");
     critters.insert (critters.begin (), "bear");
     critters.insert (critters.begin (), "cat");
 
     // Print out the list.
-    std::cout << critters << std::endl;
+    std::cout << critters << '\n';
 
     // Change cat to cougar.
     *std::find (critters.begin (),critters.end (), "cat") = "cougar";
-    std::cout << critters << std::endl;
+    std::cout << critters << '\n';
 
     // Put a zebra at the beginning, an ocelot ahead of antelope,
     // and a rat at the end.
@@ -75,20 +85,20 @@
     critters.insert (std::find (critters.begin (), critters.end (),
                                 "antelope"), "ocelot");
     critters.push_back ("rat");
-    std::cout << critters << std::endl;
+    std::cout << critters << '\n';
 
     // Sort the list (Use list's sort function since the 
     // generic algorithm requires a random access iterator 
     // and list only provides bidirectional)
     critters.sort ();
-    std::cout << critters << std::endl;
+    std::cout << critters << '\n';
 
     // Now let's erase half of the critters.
     StringList::size_type half = critters.size () / 2;
     for (StringList::size_type i = 0; i != half; ++i)
         critters.erase (critters.begin ());
 
-    std::cout << critters << std::endl;
+    std::cout << critters << '\n';
   
     return 0;
 }