Method usage

apps/gdalargumentparser.cpp:106–116

/************************************************************************/

std::string GDALArgumentParser::usage() const
{
    std::string ret(ArgumentParser::usage());
    if (!m_osExtraUsageHint.empty())
    {
        ret += '\n';
        ret += '\n';
        ret += m_osExtraUsageHint;
    }
    return ret;
}

/************************************************************************/
/*                        add_extra_usage_hint()                        */