Method indent

unittests/catch.hpp:5344–5347

            }

            auto indent() const -> size_t {
                auto initial = m_pos == 0 && m_stringIndex == 0 ? m_column.m_initialIndent : std::string::npos;
                return initial == std::string::npos ? m_column.m_indent : initial;
            }

            auto addIndentAndSuffix(std::string const &plain) const -> std::string {
                return std::string( indent(), ' ' ) + (m_suffix ? plain + "-" : plain);