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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Unexpected -Wunused-value with -std=c++17"
href="https://bugs.llvm.org/show_bug.cgi?id=35073">35073</a>
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<th>Summary</th>
<td>Unexpected -Wunused-value with -std=c++17
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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>Linux
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>enhancement
</td>
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>-New Bugs
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>stephan.bergmann.secondary@googlemail.com
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<th>CC</th>
<td>llvm-bugs@lists.llvm.org
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<div>
<pre>At least with recent Clang trunk towards 6.0:
<span class="quote">> $ cat test.cc
> struct B {};
> struct Ref { Ref(B *); };
> struct D: B { operator Ref() { return this; } };
> void f() { Ref(*new D); }</span >
>
<span class="quote">> $ clang++ -std=c++14 -fsyntax-only test.cc</span >
>
<span class="quote">> $ clang++ -std=c++17 -fsyntax-only test.cc
> test.cc:4:12: warning: expression result unused [-Wunused-value]
> void f() { Ref(*new D); }
> ^ ~~~~~~
> 1 warning generated.</span ></pre>
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