<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 - tuple comparison operators return true for tuples of different sizes"
href="https://bugs.llvm.org/show_bug.cgi?id=39183">39183</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>tuple comparison operators return true for tuples of different sizes
</td>
</tr>
<tr>
<th>Product</th>
<td>libc++
</td>
</tr>
<tr>
<th>Version</th>
<td>7.0
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux
</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>All Bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>tonyelewis@hotmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org, mclow.lists@gmail.com
</td>
</tr></table>
<p>
<div>
<pre>The following compiles cleanly under `clang++ -stdlib=libc++ -S a.cpp` :
#include <tuple>
static_assert( std::tuple<int>{ 1 } == std::tuple<int, int>{ 1, 2 }, "" );
static_assert( std::tuple<int>{ 0 } != std::tuple<int, int>{ 1, 2 }, "" );
static_assert( std::tuple<int>{ 0 } < std::tuple<int, int>{ 1, 2 }, "" );
static_assert( std::tuple<int>{ 2 } >= std::tuple<int, int>{ 1, 2 }, "" );
..demonstrating that these comparison operators are returning true for pairs of
tuples of different sizes. This feels particularly problematic in the case of
operator==().
Under "tuple.rel", the standard says that these operators require
`sizeof...(TTypes) == sizeof...(UTypes)`, though I must confess I don't know
whether the standard mandates detection and reporting of violations of
requirements like these. Either way, I think it'd be very much better to do so
in this case.
I can reproduce this on Godbolt with "clang version 8.0.0 (trunk 343649)" (and
Clangs 6 and 7).
Thanks very much for all work on libc++.</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>