<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 - Overload resolution ignores "rewritten candidate" tiebreaker when functions are constrained"
href="https://bugs.llvm.org/show_bug.cgi?id=44761">44761</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Overload resolution ignores "rewritten candidate" tiebreaker when functions are constrained
</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>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>Casey@Carter.net
</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>Created <span class=""><a href="attachment.cgi?id=23082" name="attach_23082" title="Repro">attachment 23082</a> <a href="attachment.cgi?id=23082&action=edit" title="Repro">[details]</a></span>
Repro
Compiling this well-formed TU:
#include <compare>
template<int I>
struct T {
bool operator<(T const&) const;
std::strong_ordering operator<=>(T const&) const;
};
bool f(T<2> const& x) {
return x < x; // Fine
}
template<int I>
struct S {
bool operator<(S const&) const requires(I != 0);
std::strong_ordering operator<=>(S const&) const requires(I != 1);
};
bool f(S<2> const& x) {
return x < x; // Ambiguous??!?
}
with "-std=c++2a" diagnoses:
repro.cpp(20,14): error: use of overloaded operator '<' is ambiguous (with
operand types 'const S<2>' and 'const S<2>')
return x < x; // Ambiguous??!?
~ ^ ~
repro.cpp(15,10): note: candidate function
bool operator<(S const&) const requires(I != 0);
^
repro.cpp(16,26): note: candidate function
std::strong_ordering operator<=>(S const&) const requires(I != 1);
^
repro.cpp(16,26): note: candidate function (with reversed parameter order)
1 error generated.</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>