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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - -Wunused-lambda-capture on const variable"
href="https://bugs.llvm.org/show_bug.cgi?id=41623">41623</a>
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<th>Summary</th>
<td>-Wunused-lambda-capture on const variable
</td>
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<th>Product</th>
<td>clang
</td>
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<th>Version</th>
<td>trunk
</td>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Windows NT
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>enhancement
</td>
</tr>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>-New Bugs
</td>
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>jvapen@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>htmldeveloper@gmail.com, llvm-bugs@lists.llvm.org, neeilans@live.com, richard-llvm@metafoo.co.uk
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<p>
<div>
<pre>Reproduction on compiler explorer: <a href="https://gcc.godbolt.org/z/OEYl7K">https://gcc.godbolt.org/z/OEYl7K</a>
In the example below, Clang (7.0.0 and trunk) do not require 'c' to be
captured.
Removing it, results however in a compilation failure with MSVC 2017.
t.cpp
-----
bool f()
{
const auto c = 42;
return [c](int v) { return v == c; }(42);
}
compile.sh
-----------
clang++ -O3 -std=c++2a -Wunused-lambda-capture t.cpp
compile.bat
-----------
cl /O2 t.cpp
Warning:
--------
t.cpp:5:13: warning: lambda capture 'c' is not required to be captured for this
use [-Wunused-lambda-capture]
return [c](int v) { return v == c; }(42);
^
1 warning generated.</pre>
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