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<p>Hi Hugo,</p>
<p>I took the liberty of joining your two messages into one, for the curious this email is in-reply to:</p>
<ul>
<li>https://mailman.videolan.org/pipermail/vlc-devel/2018-July/120262.html</li>
<li>https://mailman.videolan.org/pipermail/vlc-devel/2018-July/120261.html</li>
</ul>
<p>On 2018-07-13 10:12, Hugo Beauzée-Luyssen wrote:</p>
<blockquote style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;color:#500050">
<pre><code> That's my current plan, new file, new namespace for C++ helpers!
Although the issue here is that having this function non-static or in
a non-anonymous namespace will trigger a warning if -Wnoexcept-type is
enabled (which it is when using -Wall) so maybe this functions will be
in an anonymous namespace? Or we can disable the warning specifically,
which I believe would be safe since we only care about our C ABI
(AFAIK)</code></pre>
</blockquote>
<p>Just put the named namespace within an anonymous namespace, internal linkage, and in a namespace; best of both worlds.</p>
<pre><code> namespace { namespace hugos_awesome_things { ... } }</code></pre>
<blockquote style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;color:#500050">
<pre><code> So if I understand correctly, the correct noexcept expression would
be something along the line of
noexcept( std::is_reference<T>::value == false ||
std::is_lvalue_reference<decltype(Releaser)>::value == true )</code></pre>
</blockquote>
<p>You can simply mark the function as <code>noexcept</code>, that’s it. If there is an exception from constructing the <code>std::unique_ptr</code> all bets are off anyhow (as that exception from within the <code>noexcept</code> marked <em>unique_ptr</em> constructors causes <em>undefined-behavior</em>).</p>
<blockquote style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;color:#500050">
<pre><code> And probably a static_assert should be added to warrant that in case
of a non-ref type, copy/move ctors is non-throwing?</code></pre>
</blockquote>
<p>Yes, you could add a <code>static_assert</code> to prevent what has been described, but I think it is enough to simple document the fact that a <code>std::unique_ptr</code> will be created with the parameters passed.</p>
<p>By the way, Personally I would implement the two overloads involving <code>&free</code> by using the custom ones; less typing!</p>
<p>Best Regards,<br />
Mr. Lazy</p>
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