feedc0de/boost_system
1
0
Fork 0
forked from boostorg/system
Code Pull Requests Activity

System: add throws object specification, including semantics

Browse Source 
[SVN r49138]
This commit is contained in:
Beman Dawes
2008-10-05 13:02:01 +00:00
parent ee16863a40
commit a753ffd26f
1 changed files with 38 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

47
doc/reference.html
View File

@ -57,6 +57,8 @@
&nbsp;&nbsp;&nbsp;<a href="#Class-error_condition-constructors">Class <code>error_condition</code> constructors</a><br>
&nbsp;&nbsp;&nbsp;<a href="#Class-error_condition-modifiers">Class <code>error_condition</code> modifiers</a><br>
&nbsp;&nbsp;&nbsp;<a href="#Class-error_condition-observers">Class <code>error_condition</code> observers</a><br>
<a href="#throws-object"><code>throws</code> object</a><br>
<a href="#Semantics-of-throws">Semantics of <code>throws</code> object</a><br>
<a href="#Non-member-functions">Non-member functions</a><br>
<a href="#Header-system_error">Header &lt;boost/system/system_error.hpp&gt;</a><br>
&nbsp;&nbsp;&nbsp;<a href="#Class-system_error">Class <code>system_error</code></a><br>
@ -223,6 +225,11 @@ provided, so users may ignore these macros if they prefer.</p>
template<> struct is_error_condition_enum<posix::posix_errno>&lt;errc::errc_t&gt;
{ static const bool value = true; };
// predefined error_code object used as &quot;throw on error&quot; tag
extern error_code <a href="#throws-object">throws</a>;
// <a href="#Non-member-functions">non-member functions</a>
bool operator==( const error_code &amp; lhs, const error_code &amp; rhs );
bool operator==( const error_code &amp; code, const error_condition &amp; condition );
bool operator==( const error_condition &amp; condition, const error_code &amp; code );
@ -370,7 +377,7 @@ non-member functions</a></h3>
<h3><a name="Class-error_category-predefined-objects">Class <code>error_category</code>
predefined objects</a></h3>
<p>Predefined objects <code>system_category</code>
and <code>generic_category</code> identify operating system error codes and portable error conditions, respectively.</p>
and <code>generic_category</code> identify system specific error codes and portable error conditions, respectively.</p>
<h2><a name="Class-error_code">Class <code>
error_code</code></a></h2>
<p>The class <code>error_code</code> describes an object used to hold error code
@ -603,7 +610,29 @@ observers</a></h3>
eliminating some sources of user error. One possible implementation choice for
this type is pointer to member. <i>--end note</i> <i>]</i></p>
</blockquote>
<h2><a name="Non-member-functions">Non-member functions</a></h2>
<h2><a name="throws-object"><code>throws</code> object</a></h2>
<pre>extern error_code throws;</pre>
<p>The predefined <code>error_code</code> object <code>throws</code> is supplied
for use as a &quot;throw on error&quot; tag.</p>
<h2><a name="Semantics-of-throws">Semantics of <code>throws</code></a> object</h2>
<p>Functions that specify an argument in the form <code>error_code&amp; ec=throws</code>,
with appropriate namespace qualifiers, have the following error handling
semantics:</p>
<blockquote>
<p><i>Effects:</i> If <code>ec != throws</code>:</p>
<ul>
<li>If an error occurs, and sets <code>ec</code> to an appropriate <code>
<a href="#Class-error_code">error_code</a></code> that identifies the error
value and category. The category should be the most specific <code>
<a href="#Class-error_category">error_category</a></code> applicable to the
particular error.</li>
<li>if an error does not occur, <code>ec.clear()</code>.</li>
</ul>
<p><i>Throws:</i> If <code>ec == throws</code>, throws an exception of type
<code><a href="#Class-system_error">system_error</a></code> or of a type
derived from <code><a href="#Class-system_error">system_error</a></code>.</p>
</blockquote>
<h2><a name="Non-member-functions">Non-member functions</a></h2>
<pre>bool operator==( const error_code &amp; lhs, const error_code &amp; rhs );</pre>
<blockquote>
<p><i>Returns:</i> <code>lhs.category() == rhs.category() &amp;&amp; lhs.value() ==
@ -677,8 +706,7 @@ bool operator!=( const error_condition &amp; condition, const error_code &amp; c
<h3><a name="Class-system_error">Class <code>
system_error</code></a></h3>
<p>The class <code>system_error</code> describes an exception object used to
report error conditions that have an associated error code. Such error
conditions typically originate from the operating system or other low-level
report errors that have an associated <code><a href="#Class-error_code">error_code</a></code>. Such errors typically originate from operating system or other low-level
application program interfaces.</p>
<blockquote>
<pre>namespace boost
@ -754,14 +782,15 @@ application program interfaces.</p>
</blockquote>
<hr>
<p><EFBFBD> Copyright Beman Dawes, 2006, 2007<br>
Distributed under the Boost Software License, Version 1.0. See
<a href="http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a></p>
<p>Revised
<!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%B %d, %Y" startspan -->June 25, 2008<!--webbot bot="Timestamp" endspan i-checksum="14296" --> </font>
<!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%B %d, %Y" startspan -->October 05, 2008<!--webbot bot="Timestamp" endspan i-checksum="30983" --> </font>
</p>
<p><EFBFBD> Copyright Beman Dawes, 2006, 2007, 2008</p>
<p>Distributed under the Boost Software License, Version 1.0. See
<a href="http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a></p>
</body>
</html>