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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Inheriting from vector of move-only type leads to copy constructor being used"
href="https://bugs.llvm.org/show_bug.cgi?id=44540">44540</a>
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<th>Summary</th>
<td>Inheriting from vector of move-only type leads to copy constructor being used
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<th>Product</th>
<td>clang
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<th>Version</th>
<td>trunk
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<th>Hardware</th>
<td>PC
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<th>OS</th>
<td>Linux
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<th>Status</th>
<td>NEW
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<th>Severity</th>
<td>normal
</td>
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>C++
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>weiss@wsoptics.de
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<th>CC</th>
<td>blitzrakete@gmail.com, dgregor@apple.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
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<p>
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<pre>The following code does not compile with clang + libstdc++:
#include <vector>
struct MoveOnly
{
MoveOnly() = default;
MoveOnly(MoveOnly const &) = delete;
MoveOnly(MoveOnly &&) = default;
MoveOnly & operator=(MoveOnly const &) = delete;
MoveOnly & operator=(MoveOnly &&) = default;
};
template <typename T>
class V : public std::vector<T>
{
using std::vector<T>::vector;
explicit V(std::vector<T> const & v) : std::vector<T>(v) {}
explicit V(std::vector<T> && v) : std::vector<T>(std::move(v)) {}
};
void f()
{
V<MoveOnly> v{};
}
It does however compile with gcc and also with clang + libc++. (But then again
not with MSVC.)
I think there's no reason for the copy constructor to be used here though.
See also
<a href="https://godbolt.org/z/m_G99y">https://godbolt.org/z/m_G99y</a></pre>
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