function_base.hpp:

- Remove safe_bool conversion and operator! from class function_base

function_template.hpp:
  - Add safe_bool conversion and operator!
  - operator! returns bool, not safe_bool (Peter Dimov)

reference.html:
  - Document above change


[SVN r15356]
This commit is contained in:
Douglas Gregor
2002-09-16 03:44:18 +00:00
parent e16a46fbe8
commit f36e83fb27
3 changed files with 36 additions and 35 deletions

View File

@ -17,8 +17,6 @@
{
<b>typedef</b> <em>implementation-defined</em> safe_bool;
<a href="#empty"><b>bool</b> empty() <b>const</b></a>;
<a href="#bool"><b>operator</b> safe_bool() <b>const</b></a>;
<a href="#not">safe_bool <b>operator!</b>() <b>const</b></a>;
};
// For <i>N</i> in [0, <i>MAX_ARGS</i>]
@ -66,6 +64,10 @@
<a href="#functionN_swap"><b>void</b> swap(function<i>N</i><b>&amp;</b>)</a>;
<a href="#functionN_clear"><b>void</b> clear()</a>;
<i>// Boolean context</i>
<a href="#bool"><b>operator</b> safe_bool() <b>const</b></a>;
<a href="#not"><b>bool</b> <b>operator!</b>() <b>const</b></a>;
<i>// Invocation</i>
<a href="#functionN_call_const">result_type <b>operator</b>()(Arg1 a1, Arg2 a2, <i>...</i>, Arg<i>N</i> a<i>N</i>) <b>const</b></a>;
};
@ -146,20 +148,6 @@
<li><b>Throws</b>: will not throw.</li>
</ul>
<p> <a name="bool"><code><b>operator</b> safe_bool() <b>const</b></code></a>
<ul>
<li><b>Returns</b>: <code>safe_bool</code> equivalent of <code>!<a href="#empty">empty</a>()</code></li>
<li><b>Throws</b>: will not throw.</li>
<li><b>Notes</b>: The <code>safe_bool</code> type can be used in contexts where a <b>bool</b> is expected (e.g., an <b>if</b> condition); however, implicit conversions (e.g., to <b>int</b>) that can occur with <b>bool</b> are not allowed, eliminating some sources of user error.
</ul>
<p> <a name="not"><code>safe_bool <b>operator!</b>() <b>const</b></code></a>
<ul>
<li><b>Returns</b>: <code>safe_bool</code> equivalent of <code><a href="#empty">empty</a>()</code></li>
<li><b>Throws</b>: will not throw.</li>
<li><b>Notes</b>: See <a href="#bool"><code>safe_bool</code> conversion</a>
</ul>
<h2><a name="functionN">Class template <code>function<i>N</i></code></a></h2>
<p> Class template <code>function<i>N</i></code> is actually a family of related classes <code>function0</code>, <code>function1</code>, etc., up to some implementation-defined maximum. In this context, <code><i>N</i></code> refers to the number of parameters and <code>f</code> refers to the implicit object parameter.
@ -239,6 +227,19 @@
<li><b>Postconditions</b>: <code><a href="#empty">empty</a>()</code>.</li>
</ul>
<p> <a name="bool"><code><b>operator</b> safe_bool() <b>const</b></code></a>
<ul>
<li><b>Returns</b>: <code>safe_bool</code> equivalent of <code>!<a href="#empty">empty</a>()</code></li>
<li><b>Throws</b>: will not throw.</li>
<li><b>Notes</b>: The <code>safe_bool</code> type can be used in contexts where a <b>bool</b> is expected (e.g., an <b>if</b> condition); however, implicit conversions (e.g., to <b>int</b>) that can occur with <b>bool</b> are not allowed, eliminating some sources of user error.
</ul>
<p> <a name="not"><code><b>bool</b> <b>operator!</b>() <b>const</b></code></a>
<ul>
<li><b>Returns</b>: <code>this-&gt;empty()</code></li>
<li><b>Throws</b>: will not throw.</li>
</ul>
<p> <a name="functionN_call_const"><code> result_type <b>operator</b>()(Arg1 a1, Arg2 a2, <i>...</i>, Arg<i>N</i> a<i>N</i>) <b>const</b>;</code></a>
<ul>
<li><b>Requires</b>: <code>!<a href="#empty">empty</a>()</code>.</li>