Method isBoundary

unittests/catch.hpp:5306–5314

            auto line() const -> std::string const& { return m_column.m_strings[m_stringIndex]; }

            auto isBoundary( size_t at ) const -> bool {
                assert( at > 0 );
                assert( at <= line().size() );

                return at == line().size() ||
                       ( isWhitespace( line()[at] ) && !isWhitespace( line()[at-1] ) ) ||
                       isBreakableBefore( line()[at] ) ||
                       isBreakableAfter( line()[at-1] );
            }

            void calcLength() {
                assert( m_stringIndex < m_column.m_strings.size() );