<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 fails to compile code that uses std::apply on a member variable from a __restrict member function"
href="https://bugs.llvm.org/show_bug.cgi?id=43066">43066</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Clang fails to compile code that uses std::apply on a member variable from a __restrict member function
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>All
</td>
</tr>
<tr>
<th>OS</th>
<td>All
</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>mike.k@digitalcarbide.com
</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>The following code fails to compile under Clang with '-std=c++2a' and
'-std=c++17':
#include <tuple>
struct foo {
const std::tuple<int> v_;
constexpr foo (int v) : v_(v) {}
bool operator == (int value) const __restrict {
return std::apply([](auto) {return true;}, v_);
}
};
bool test (int v) {
return foo{0} == v;
}
If the '__restrict' is removed from the 'operator ==', it compiles.
This code successfully compiles under GCC and MSVC:
<a href="https://godbolt.org/z/S8bGiA">https://godbolt.org/z/S8bGiA</a>
The core errors appear to be:
tuple:1271:44: error: implicit instantiation of undefined template
'std::tuple_size<__restrict std::tuple<int> >'
inline constexpr size_t tuple_size_v = tuple_size<_Tp>::value;
tuple:1686:44: error: non-type template argument is not a constant expression
using _Indices = make_index_sequence<tuple_size_v<decay_t<_Tuple>>>;
tuple:1687:14: error: no matching function for call to '__apply_impl'
return std::__apply_impl(std::forward<_Fn>(__f),</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>