<html>
    <head>
      <base href="http://llvm.org/bugs/" />
    </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 --- - Cannot multiply a valarray and a single element slice_array"
   href="http://llvm.org/bugs/show_bug.cgi?id=20946">20946</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Cannot multiply a valarray and a single element slice_array
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>libc++
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>unspecified
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>Macintosh
          </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>All Bugs
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>mclow.lists@gmail.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvmbugs@cs.uiuc.edu, mclow.lists@gmail.com
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr></table>
      <p>
        <div>
        <pre>#include <valarray>

int main(int argc, char *argv[]) {
       std::valarray<double> a(4, 10);
       std::valarray<double> b(4, 20);
       a *= b[std::slice(1,1,1)];
       return 0;
}

fails to compile, with error:
test.cpp:6:4: error: no viable overloaded '*='
       a *= b[std::slice(1,1,1)];
       ~ ^  ~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/v1/valarray:871:15: note: candidate function not viable: no
known conversion from 'slice_array<value_type>' to 'const value_type'
     (aka 'const double') for 1st argument
   valarray& operator*= (const value_type& __x);
             ^
/usr/include/c++/v1/valarray:885:9: note: candidate template ignored: disabled
by 'enable_if' [with _Expr = std::__1::slice_array<double>]
       __is_val_expr<_Expr>::value,
       ^

Compiles with gcc 4.8 and 4.9</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>