<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 - clang accepts an abstract class in function return type"
href="https://bugs.llvm.org/show_bug.cgi?id=47843">47843</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>clang accepts an abstract class in function return type
</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>enhancement
</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>tangyixuan@mail.dlut.edu.cn
</td>
</tr>
<tr>
<th>CC</th>
<td>blitzrakete@gmail.com, dgregor@apple.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
</td>
</tr></table>
<p>
<div>
<pre>Hi, the following code maybe is ill-formed, since the abstract class shall not
be used as a function return type in most cases. Clang accepts it without error
diagnostics.
$ cat s.cpp
template<typename T>
struct S{};
struct A
{
virtual void func() = 0;
};
int main()
{
S<A(int)> s;
}
$ clang++ -c s.cpp
<success>
$ g++ -c s.cpp
s.cpp: In function ‘int main()’:
s.cpp:11:5: error: invalid abstract return type ‘A’
23 | S<A(int)> s;
| ^
s.cpp:4:8: note: because the following virtual functions are pure within ‘A’:
16 | struct A
| ^
s.cpp:6:16: note: ‘virtual void A::f()’
18 | virtual void f() = 0;
|</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>