<table><tr><td style="">markg added inline comments.
</td><a style="text-decoration: none; padding: 4px 8px; margin: 0 8px 8px; float: right; color: #464C5C; font-weight: bold; border-radius: 3px; background-color: #F7F7F9; background-image: linear-gradient(to bottom,#fff,#f1f0f1); display: inline-block; border: 1px solid rgba(71,87,120,.2);" href="https://phabricator.kde.org/D5461" rel="noreferrer">View Revision</a></tr></table><br /><div><strong>INLINE COMMENTS</strong><div><div style="margin: 6px 0 12px 0;"><div style="border: 1px solid #C7CCD9; border-radius: 3px;"><div style="padding: 0; background: #F7F7F7; border-color: #e3e4e8; border-style: solid; border-width: 0 0 1px 0; margin: 0;"><div style="color: #74777d; background: #eff2f4; padding: 6px 8px; overflow: hidden;"><a style="float: right; text-decoration: none;" href="https://phabricator.kde.org/D5461#inline-22371" rel="noreferrer">View Inline</a><span style="color: #4b4d51; font-weight: bold;">graesslin</span> wrote in <span style="color: #4b4d51; font-weight: bold;">pointer_input.cpp:440</span></div>
<div style="margin: 8px 0; padding: 0 12px; color: #74777D;"><blockquote style="border-left: 3px solid #a7b5bf; color: #464c5c; font-style: italic; margin: 4px 0 12px 0; padding: 4px 12px; background-color: #f8f9fc;"><p style="padding: 0; margin: 8px;">Just curious, why do you define end as opposed tho this:</p></blockquote>
<p style="padding: 0; margin: 8px;">Because <a href="https://phabricator.kde.org/p/broulik/" style="
border-color: #f1f7ff;
color: #19558d;
background-color: #f1f7ff;
border: 1px solid transparent;
border-radius: 3px;
font-weight: bold;
padding: 0 4px;" rel="noreferrer">@broulik</a> tends to point out that it is not cached.</p>
<blockquote style="border-left: 3px solid #a7b5bf; color: #464c5c; font-style: italic; margin: 4px 0 12px 0; padding: 4px 12px; background-color: #f8f9fc;"><p style="padding: 0; margin: 8px;">Another route you can go which looks much cleaner imho (requires Qt 5.7 because of qAsConst):</p></blockquote>
<p style="padding: 0; margin: 8px;">does that work in a sensible way for a QHash? The most lean way would have been:</p>
<div class="remarkup-code-block" style="margin: 12px 0;" data-code-lang="text" data-sigil="remarkup-code-block"><pre class="remarkup-code" style="font: 11px/15px "Menlo", "Consolas", "Monaco", monospace; padding: 12px; margin: 0; background: rgba(71, 87, 120, 0.08);">if (std::any_of(m_buttons.constBegin(), m_buttons.constEnd(), [] ...))</pre></div>
<p style="padding: 0; margin: 8px;">But that doesn't work with QHash. So I kind of doubt QHash and qAsConst do something sensible.</p></div></div>
<div style="margin: 8px 0; padding: 0 12px;"><p style="padding: 0; margin: 8px;">This is where STL and Qt apparently diverge a bit.</p>
<p style="padding: 0; margin: 8px;">for (auto value : qAsConst(m_buttons)) {<br />
// ...<br />
}</p>
<p style="padding: 0; margin: 8px;">Gives you the values in the map. Not the keys. And that is because it's a QHash container which apparently behaves like that.<br />
If it were an std::unordered_map it would have given you a std::pair where first would be the key, second would be the value.</p>
<p style="padding: 0; margin: 8px;">However, in *this* case you are only using the value thus you are fine when using:<br />
for (auto value : qAsConst(m_buttons)) {<br />
// ...<br />
}</p>
<p style="padding: 0; margin: 8px;">Since you seem to mention optimization (you shouldn't have done that ;)), this is the most efficient version, and i looked it up [1], hehe:<br />
for (cont auto &value : qAsConst(m_buttons)) {<br />
// ...<br />
}</p>
<p style="padding: 0; margin: 8px;">In fact. You likely always want this version of the range-based-for loop. And "for (auto&& value: ...)" if you want to modify them in place. You nearly never want a plain range-based-for without a reference symbol in there because that makes a copy.</p>
<p style="padding: 0; margin: 8px;">Hope that helps :)</p>
<p style="padding: 0; margin: 8px;">[1] Read <a href="https://blog.petrzemek.net/2016/08/17/auto-type-deduction-in-range-based-for-loops/" class="remarkup-link" target="_blank" rel="noreferrer">https://blog.petrzemek.net/2016/08/17/auto-type-deduction-in-range-based-for-loops/</a> for the details</p></div></div></div></div></div><br /><div><strong>REPOSITORY</strong><div><div>R108 KWin</div></div></div><br /><div><strong>REVISION DETAIL</strong><div><a href="https://phabricator.kde.org/D5461" rel="noreferrer">https://phabricator.kde.org/D5461</a></div></div><br /><div><strong>To: </strong>graesslin, KWin, Plasma<br /><strong>Cc: </strong>broulik, markg, plasma-devel, kwin, spstarr, progwolff, lesliezhai, ali-mohamed, hardening, jensreuterberg, abetts, sebas, apol<br /></div>