This fixes hopefully the compilation of check_trivstring on cygwin and
solaris. Previously I did not use the explicit instantiation, because c_str()
is used by other explicitly instantiated methiods, but for some reason this
does not seem to suffice.
+template char const * trivial_string<char>::c_str() const;
+template char_type const * trivial_string<char_type>::c_str() const;
template<typename Char> Char const * trivial_string<Char>::c_str() const
{
if (use_sso())
template<typename Char> Char const * trivial_string<Char>::c_str() const
{
if (use_sso())