PVS-Studio warning V530 for wxWidgets

wxString m_strKey;

void wxRegKey::SetHkey(WXHKEY hKey)
{
  ...

  // reset old data
  m_strKey.empty();
  m_dwLastError = 0;
}

This is what should have been written here: m_strKey.clear();

This suspicious code was found in wxWidgets project by PVS-Studio static code analyzer.
Warning message is:
V530 The return value of function 'empty' is required to be utilized. base registry.cpp 329

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/