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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - const-default-constructible class has deleted constructor"
href="https://bugs.llvm.org/show_bug.cgi?id=39362">39362</a>
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<th>Summary</th>
<td>const-default-constructible class has deleted constructor
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
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<th>Version</th>
<td>unspecified
</td>
</tr>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Windows NT
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>C++
</td>
</tr>
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>zturner@google.com
</td>
</tr>
<tr>
<th>CC</th>
<td>dgregor@apple.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
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<div>
<pre><a href="https://godbolt.org/z/s6Hjm0">https://godbolt.org/z/s6Hjm0</a>
struct A {
#ifdef DEFAULT
A() = default; // error
#else
A(){}; //ok
#endif
};
struct b {
const A a;
};
struct c : b {
c(){}
};
Per Richard Smith, this is a bug in the C++ standard, because
<a href="http://eel.is/c++draft/class.default.ctor#2.4">http://eel.is/c++draft/class.default.ctor#2.4</a> and
<a href="http://eel.is/c++draft/dcl.init#def:const-default-constructible">http://eel.is/c++draft/dcl.init#def:const-default-constructible</a> conflict with
each other. Clang conforms to the written behavior (constructor is deleted)
while other compilers conform to the intended behavior (class is
const-default-constructible).
Clang should conform to the intended behavior, even if the standard does not
(yet) reflect this.
This may or may not be related to <a class="bz_bug_link
bz_status_NEW "
title="NEW - Class with a default constructible const member is not default constructible"
href="show_bug.cgi?id=33039">Bug 33039</a>.</pre>
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