<html>
<head>
<base href="https://bugs.llvm.org/">
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Lambda incorrectly passes SNIFAE check for bool conversion in Objective-C++"
href="https://bugs.llvm.org/show_bug.cgi?id=44567">44567</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Lambda incorrectly passes SNIFAE check for bool conversion in Objective-C++
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>Macintosh
</td>
</tr>
<tr>
<th>OS</th>
<td>MacOS X
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>-New Bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>rajveer_aujla@hotmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>htmldeveloper@gmail.com, llvm-bugs@lists.llvm.org, neeilans@live.com, richard-llvm@metafoo.co.uk
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=23020" name="attach_23020" title="Code sample">attachment 23020</a> <a href="attachment.cgi?id=23020&action=edit" title="Code sample">[details]</a></span>
Code sample
The attached file has a SNIFAE check to see if a type T can be converted to a
bool (`bool(T)`), and a set of `execute` functions where the correct one is
picked based on this check. When compiled as C++17, this check correctly fails
when the type T is a lambda and the file type is .cpp.
If the file is renamed to .mm however (to make the file be compiled as
Objective-C++), the SNIFAE check incorrectly passes, which leads to the
incorrect `execute` function being invoked. This then fails as the lambda is
attempted to be converted to an Objective-C block, with the following error:
Call to implicitly-deleted copy constructor of 'const (lambda at
.../main.mm:68:25)'
This error message is correct, however the compiler shouldn't get to this stage
since the template check should fail for Objective-C++ too.</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are on the CC list for the bug.</li>
</ul>
</body>
</html>