<html>
<head>
<base href="https://llvm.org/bugs/" />
</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 --- - Single-element initializer_list invokes wrong constructor" href="https://urldefense.proofpoint.com/v2/url?u=https-3A__llvm.org_bugs_show-5Fbug.cgi-3Fid-3D23812&d=AwMBaQ&c=8hUWFZcy2Z-Za5rBPlktOQ&r=pF93YEPyB-J_PERP4DUZOJDzFVX5ZQ57vQk33wu0vio&m=NiDVi26xLLTB-zgDGQ5j93nV9z8Bzk8Egjskq5Hek5M&s=d3Vk8V9VrzStIkXSOHjWZllLCmhUTedxWxVu0Q6IuGo&e=">23812</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Single-element initializer_list invokes wrong constructor
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>All
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>release blocker
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>C++11
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>j4cbo@dropbox.com
</td>
</tr>
<tr>
<th>CC</th>
<td>dgregor@apple.com, llvmbugs@cs.uiuc.edu
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>Test case:
#include <initializer_list>
#include <iostream>
struct Q {
Q() { std::cout << "default\n"; }
Q(Q const&) { std::cout << "copy\n"; }
Q(Q&&) { std::cout << "move\n"; }
Q(std::initializer_list<Q>) { std::cout << "initializer list\n"; }
};
int main() {
Q x = Q { Q() };
}
"Q { Q() }" should invoke the initializer_list constructor, but recent Clang
(trunk as of today, r239482) treats it as a move instead. For comparison, clang
3.6 and older, gcc 4.9, 5.1, and MSVC2015 all select the initializer_list
constructor.
This is really bad for us, as it silently changes the meaning of code in a
subtle way (manifests as making our JSON library elide single-element array
literals). :(</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>