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    <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 - Error when passing 0 args to a variadic macro parameters with `-std=c++20 -pedantic-errors`"
   href="https://bugs.llvm.org/show_bug.cgi?id=51609">51609</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Error when passing 0 args to a variadic macro parameters with `-std=c++20 -pedantic-errors`
          </td>
        </tr>

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

        <tr>
          <th>Version</th>
          <td>12.0
          </td>
        </tr>

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

        <tr>
          <th>OS</th>
          <td>Linux
          </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>blckcat@inbox.ru
          </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>Starting from C++20, it's allowed to pass 0 arguments to the variadic macro
parameter.

I.e. following should be allowed:
    #define FOO(x, ...)
    FOO(42)

Clang successfully compiles it by default, but if you add `-std=c++20
-pedantic-errors`, it starts (incorrectly) complaining:

    error: must specify at least one argument for '...' parameter of variadic
macro [-Werror,-Wgnu-zero-variadic-macro-arguments]

`-pedantic-errors` should only enable this diagnostic in C++17 and earlier.</pre>
        </div>
      </p>


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