'Re: Review Request 115125: Fix compilation with clang'

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List:       kwin
Subject:    Re: Review Request 115125: Fix compilation with clang
From:       "Fabian Kosmale" <0inkane () googlemail ! com>
Date:       2014-01-19 18:19:22
Message-ID: 20140119181922.13922.71830 () probe ! kde ! org
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This is an automatically generated e-mail. To reply, visit:
https://git.reviewboard.kde.org/r/115125/
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(Updated Jan. 19, 2014, 6:19 p.m.)

Status
------

This change has been marked as submitted.

Review request for kwin and Martin Gräßlin.

Repository: kde-workspace

Description
-------

Without the patch, compilation (with clang 3.3) fails with
error: return type 'const QString' must match previous return type 'QString' when \
lambda expression has  unspecified explicit return type
For an explanation why this happens, see \
https://www.mail-archive.com/llvmbugs@cs.uiuc.edu/msg22245.html. GCC seems to simply \
remove the const. In the patch I'm using a const_cast<QString &> to make the compiler \
happy, but maybe creating a new QString and returning that one would be clearer? The \
QString copy ctor is invoked anyway, as the deduced return type is QString, and the \
result of the cast is still a reference.

Diffs
-----

  kwin/rules.cpp d09548b 

Diff: https://git.reviewboard.kde.org/r/115125/diff/

Testing
-------

It still compiles with GCC; though I couldn't run the unit tests so far.

Thanks,

Fabian Kosmale

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<div>Review request for kwin and Martin Gräßlin.</div>
<div>By Fabian Kosmale.</div>

<p style="color: grey;"><i>Updated Jan. 19, 2014, 6:19 p.m.</i></p>

<div style="margin-top: 1.5em;">
 <b style="color: #575012; font-size: 10pt;">Repository: </b>
kde-workspace
</div>

<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Description </h1>
 <table width="100%" bgcolor="#ffffff" cellspacing="0" cellpadding="10" \
style="border: 1px solid #b8b5a0">  <tr>
  <td>
   <pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: \
-moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: \
                break-word;">Without the patch, compilation (with clang 3.3) fails \
                with
error: return type &#39;const QString&#39; must match previous return type \
&#39;QString&#39; when lambda expression has  unspecified explicit return type
For an explanation why this happens, see \
https://www.mail-archive.com/llvmbugs@cs.uiuc.edu/msg22245.html. GCC seems to simply \
remove the const. In the patch I&#39;m using a const_cast&lt;QString &amp;&gt; to \
make the compiler happy, but maybe creating a new QString and returning that one \
would be clearer? The QString copy ctor is invoked anyway, as the deduced return type \
is QString, and the result of the cast is still a reference.</pre>  </td>
 </tr>
</table>

<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Testing </h1>
<table width="100%" bgcolor="#ffffff" cellspacing="0" cellpadding="10" style="border: \
1px solid #b8b5a0">  <tr>
  <td>
   <pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: \
-moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: \
break-word;">It still compiles with GCC; though I couldn&#39;t run the unit tests so \
far.</pre>  </td>
 </tr>
</table>

<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
<ul style="margin-left: 3em; padding-left: 0;">

 <li>kwin/rules.cpp <span style="color: grey">(d09548b)</span></li>

</ul>

<p><a href="https://git.reviewboard.kde.org/r/115125/diff/" style="margin-left: \
3em;">View Diff</a></p>

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