<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 - Unclear error message"
   href="https://bugs.llvm.org/show_bug.cgi?id=39964">39964</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Unclear error message
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>clang
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>7.0
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>PC
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>Windows NT
          </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>-New Bugs
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>unassignedclangbugs@nondot.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>jvapen@gmail.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>htmldeveloper@gmail.com, llvm-bugs@lists.llvm.org, neeilans@live.com, richard-llvm@metafoo.co.uk
          </td>
        </tr></table>
      <p>
        <div>
        <pre>test.cpp
========
struct A
{
    A() = default;
    A(A&&) {}
};

struct B : A
{
    B() = default;
    B(B&&) noexcept = default;

    A a;
};

Error message:
==============
exception specification of explicitly defaulted move constructor does not match
the calculated one

see <a href="https://gcc.godbolt.org/z/lvQ6a_">https://gcc.godbolt.org/z/lvQ6a_</a>

The error message itself doesn't help me solving the problem.
I now know that B can't be nothrow-move-constructable.
However, I don't get told why this is the case.
For this specific case, I rather add 'noexcept' to class A, than removing it
from B.
Knowing where the 'calculated one' gets the different result from, allows me to
do so.</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>