<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 - no_unique_address and has_unique_object_representations"
href="https://bugs.llvm.org/show_bug.cgi?id=47722">47722</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>no_unique_address and has_unique_object_representations
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>10.0
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Windows NT
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>C++2a
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>kirshamir@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>blitzrakete@gmail.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
</td>
</tr></table>
<p>
<div>
<pre>From StackOverflow (<a href="https://stackoverflow.com/q/64195712/2069064">https://stackoverflow.com/q/64195712/2069064</a>):
#include <type_traits>
struct Empty {};
struct A : public Empty {
int x;
};
struct B {
[[no_unique_address]] Empty e;
int x;
};
static_assert (sizeof(A) == sizeof(int)); // ok
static_assert (sizeof(B) == sizeof(int)); // ok
static_assert(std::has_unique_object_representations_v<A>); // ok
static_assert(std::has_unique_object_representations_v<B>); // error
clang does not consider B to have unique object representations, but it should
here.
Note that a similar bug was opened on gcc:
<a href="https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97285">https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97285</a></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>