Use C++11 explicit conversion operator if available

[SVN r83210]
This commit is contained in:
Beman Dawes
2013-02-28 20:55:07 +00:00
parent 87130d1d73
commit 08ea984237
6 changed files with 41 additions and 31 deletions
+10 -29
View File
@@ -452,7 +452,7 @@ error_code</code> synopsis</a></h3>
cont error_category &amp; category() const noexcept;
error_condition default_error_condition() const noexcept;
string message() const;
operator unspecified-bool-type() const;
explicit operator bool() const noexcept;
private:
int val_; // <i>exposition only</i>
@@ -517,20 +517,10 @@ error_code</code> observers</a></h3>
<pre><code>string message() const;</code></pre>
<blockquote>
<p><i>Returns:</i>&nbsp; <code>category().message( value())</code>.</p>
<p><i>Throws:</i> Nothing.</p>
</blockquote>
<pre>operator unspecified-bool-type() const;</pre>
<pre>explicit operator bool() const noexcept;</pre>
<blockquote>
<p><i>Returns:</i> if <code>value() != 0</code>, returns a value that will evaluate
<code>true</code> in a boolean context; otherwise, returns a value that will
evaluate <code>false</code> in a boolean context. The value type returned shall
not be convertible to <code>int</code>.</p>
<p><i>Throws:</i> nothing.</p>
<p><i>[Note: </i>This conversion can be used in contexts where a <code>bool</code>
is expected ( e.g., an <code>if</code> condition ); however, implicit conversions
( e.g., to <code>int</code>) that can occur with <code>bool</code> are not
allowed, eliminating some sources of user error. One possible implementation
choice for this type is pointer-to-member. <i>--end note ]</i></p>
<p><i>Returns:</i> <code>value() != 0</code>.</p>
</blockquote>
<h2><a name="Class-error_condition">Class <code>error_condition</code></a></h2>
<p>The class <code>error_condition</code> describes an object used to hold
@@ -560,10 +550,10 @@ implementation specific. <i>--end note ]</i></p>
void clear() noexcept;
// observers:
int value() const noexcept;
const error_category &amp; category() const noexcept;
string message() const;
operator unspecified-bool-type () const noexcept;
int value() const noexcept;
const error_category&amp; category() const noexcept;
string message() const;
explicit operator bool() const noexcept;
private:
int val_; // <i>exposition only</i>
@@ -626,18 +616,9 @@ observers</a></h3>
<blockquote>
<p><i>Returns:</i> <code>category().message( value() )</code>.</p>
</blockquote>
<pre>operator unspecified-bool-type () const;</pre>
<pre>explicit operator bool() const noexcept;</pre>
<blockquote>
<p><i>Returns: </i>If <code>value() != 0</code>, returns a value that will
evaluate <code>true</code> in a boolean context; otherwise, returns a value
that will evaluate <code>false</code>. The return type shall not be
convertible to <code>int</code>. </p>
<p><i>Throws:</i> Nothing.</p>
<p><i>&nbsp;[ Note:</i> This conversion can be used in contexts where a <code>bool</code>
is expected ( e.g., an if condition ); however, implicit conversions ( e.g., to
<code>int</code>) that can occur with <code>bool</code> are not allowed,
eliminating some sources of user error. One possible implementation choice for
this type is pointer to member. <i>--end note</i> <i>]</i></p>
<p><i>Returns: </i> <code>value() != 0</code>. </p>
</blockquote>
<h2><a name="throws-object"><code>throws</code> object</a></h2>
<pre>extern error_code throws;</pre>
@@ -812,7 +793,7 @@ application program interfaces.</p>
<hr>
<p>Revised
<!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%B %d, %Y" startspan -->February 27, 2013<!--webbot bot="Timestamp" endspan i-checksum="41547" --> </font>
<!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%B %d, %Y" startspan -->February 28, 2013<!--webbot bot="Timestamp" endspan i-checksum="41551" --> </font>
</p>
<p>© Copyright Beman Dawes, 2006, 2007, 2008, 2013</p>