svn commit: r544245 - /incubator/stdcxx/trunk/doc/stdlibug/18-4.html

[se...@apache.org]

Author: sebor
Date: Mon Jun  4 13:22:27 2007
New Revision: 544245

URL: http://svn.apache.org/viewvc?view=rev&rev=544245
Log:
2007-06-04  Martin Sebor  <se...@roguewave.com>

	* 18-4.html: Updated example program to match the latest code
	and added possible output.

Modified:
    incubator/stdcxx/trunk/doc/stdlibug/18-4.html

Modified: incubator/stdcxx/trunk/doc/stdlibug/18-4.html
URL: http://svn.apache.org/viewvc/incubator/stdcxx/trunk/doc/stdlibug/18-4.html?view=diff&rev=544245&r1=544244&r2=544245
==============================================================================
--- incubator/stdcxx/trunk/doc/stdlibug/18-4.html (original)
+++ incubator/stdcxx/trunk/doc/stdlibug/18-4.html Mon Jun  4 13:22:27 2007
@@ -6,54 +6,65 @@
 <A HREF="18-3.html"><IMG SRC="images/bprev.gif" WIDTH=20 HEIGHT=21 ALT="Previous file" BORDER=O></A><A HREF="noframes.html"><IMG SRC="images/btop.gif" WIDTH=56 HEIGHT=21 ALT="Top of Document" BORDER=O></A><A HREF="booktoc.html"><IMG SRC="images/btoc.gif" WIDTH=56 HEIGHT=21 ALT="Contents" BORDER=O></A><A HREF="tindex.html"><IMG SRC="images/bindex.gif" WIDTH=56 HEIGHT=21 ALT="Index page" BORDER=O></A><A HREF="VI.html"><IMG SRC="images/bnext.gif" WIDTH=25 HEIGHT=21 ALT="Next file" BORDER=O></A><DIV CLASS="DOCUMENTNAME"><B>Apache C++ Standard Library User's Guide</B></DIV>
 <H2>18.4 Example Program: Exceptions</H2>
 <BLOCKQUOTE><HR><B>
-NOTE -- This program is in the file exceptn.cpp.
+NOTE -- This program is in the file <code>tutorial/stdexcept.cpp</code>.
 </B><HR></BLOCKQUOTE>
 <A NAME="idx428"><!></A>
 <P>This following example program demonstrates the use of exceptions:</P>
 
 <UL><PRE>
-#include &lt;stdexcept&gt;
-#include &lt;string&gt;
+#include &lt;string&gt;      // for string
+#include &lt;stdexcept&gt;   // for exception, runtime_error, out_of_range
+#include &lt;iostream&gt;    // for cout
 
-static void f() { throw std::runtime_error("a runtime error"); }
 
 int main ()
 {
-  std::string s;
-  
-  // First we'll try to incite then catch an exception 
-  // from the C++ Standard Library string class.
-  // We'll try to replace at a position that is non-existent.
-  //
-  // By wrapping the body of main in a try-catch block we can be
-  // assured that we'll catch all exceptions in the exception
-  // hierarchy. You can simply catch an exception as is done 
-  // below, or you can catch each of the exceptions in which 
-  // you have an interest.
-  try
-  {
-    s.replace(100,1,1,'c');
-  }
-  catch (const std::exception&amp; e)
-  {
-    std::cout &lt;&lt; "Got an exception: " &lt;&lt; e.what() &lt;&lt; std::endl;
-  }
+    // First we'll incite and catch an exception from the C++ Standard
+    // library class std::string by attempting to replace a substring
+    // starting at a position beyond the end of the string object.
+    try {
+        std::string ().replace (100, 1, 1, 'c');
+    }
+    catch (std::out_of_range &amp;e) {
 
-  // Now we'll throw our own exception using the function 
-  // defined above.
-  try
-  {
-    f();
-  }
-  catch (const std::exception&amp; e)
-  {
-    std::cout &lt;&lt; "Got an exception: " &lt;&lt; e.what() &lt;&lt; std::endl;
-  }
- 
-  return 0;
+        // Print out the exception string, which in this implementation
+        // includes the location and the name of the function that threw
+        // the exception along with the reason for the exception.
+        std::cout &lt;&lt; "Caught an out_of_range exception: "
+                  &lt;&lt; e.what () &lt;&lt; '\n';
+    }
+    catch (std::exception &amp;e) {
+
+        std::cout &lt;&lt; "Caught an exception of an unexpected type: "
+                  &lt;&lt; e.what () &lt;&lt; '\n';
+    }
+    catch (...) {
+        std::cout &lt;&lt; "Caught an unknown exception\n";
+    }
+    
+    // Throw another exception.
+    try {
+        throw std::runtime_error ("a runtime error");
+    }
+    catch (std::runtime_error &amp;e) {
+        std::cout &lt;&lt; "Caught a runtime_error exception: "
+                  &lt;&lt; e.what () &lt;&lt; '\n';
+    }
+    catch (std::exception &amp;e) {
+        std::cout &lt;&lt; "Caught an exception of an unexpected type: "
+                  &lt;&lt; e.what () &lt;&lt; '\n';
+    } 
+    catch (...) {
+        std::cout &lt;&lt; "Caught an unknown exception\n";
+    }
+   
+    return 0;
 }
 </PRE></UL>
-
+<P>The exact output of the program is specific to the compiler used to compile it and to the location of the library headers but may look something like this:</P><UL><PRE>
+Caught an out_of_range exception: /usr/local/stdcxx/include/string.cc:422: std::string& std::string::replace(size_type, size_type, size_type, char_type): argument value 100 out of range [0, 0)
+Caught a runtime_error exception: a runtime error
+</UL></PRE>
 
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