<html>
<head>
<base href="http://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 --- - mishandling of ambiguous derived-to-base conversion in covariant return types"
href="http://llvm.org/bugs/show_bug.cgi?id=17858">17858</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>mishandling of ambiguous derived-to-base conversion in covariant return types
</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>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>C++
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>richard-llvm@metafoo.co.uk
</td>
</tr>
<tr>
<th>CC</th>
<td>dgregor@apple.com, llvmbugs@cs.uiuc.edu, rjmccall@apple.com
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>Consider:
struct A {};
struct B : A {};
struct C : A {};
struct D : B, C {} d;
struct X { virtual A *f() = 0; };
struct Y : X { virtual C *f() = 0; };
struct Z : Y { virtual D *f() { return &d; } } z;
This seems to be ill-formed, per 10.3/2 and 10.3/7: Z::f overrides both X::f
and Y::f, but D* does not have an unambiguous conversion to A*.
(Even if we thought it was valid, we produce wrong code: X::f() returns d's
B::A subobject, not its C::A subobject.)</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>