Repository: nlohmann/json
File: include/nlohmann/detail/output/serializer.hpp (C++)

Code before:
                    {
                        o->write_characters(string_buffer.data(), bytes);
                        bytes = 0;
                    }

                    // remember the byte position of this accept
                    bytes_after_last_accept = bytes;
                    undumped_chars = 0;
                    break;
                }

                case UTF8_REJECT:  // decode found invalid UTF-8 byte
                {
                    switch (error_handler)
                    {
                        case error_handler_t::strict:
                        {
                            std::string sn(3, '\0');
                            snprintf(&sn[0], sn.size(), "%.2X", byte);
                            JSON_THROW(type_error::create(316, "invalid UTF-8 byte at index " + std::to_string(i) + ": 0x" + sn));
                        }

                        case error_handler_t::ignore:
                        case error_handler_t::replace:
                        {
                            // in case we saw this chatacter the first time, we
                            // would like to read it again, because the byte
                            // may be OK for itself, but just not OK for the
                            // previous sequence
                            if (undumped_chars > 0)
                            {
                                --i;
                            }

                            // reset length buffer to the last accepted index;
                            // thus removing/ignoring the invalid characters
                            bytes = bytes_after_last_accept;

                            if (error_handler == error_handler_t::replace)
                            {
                                // add a replacement character
                                if (ensure_ascii)
                                {
                                    string_buffer[bytes++] = '\\';
                                    string_buffer[bytes++] = 'u';
                                    string_buffer[bytes++] = 'f';
                                    string_buffer[bytes++] = 'f';
                                    string_buffer[bytes++] = 'f';
                                    string_buffer[bytes++] = 'd';
                                }
                                else

Review comment (suggestion):
```suggestion
                            // in case we saw this character the first time, we
```

Code after:
                    {
                        o->write_characters(string_buffer.data(), bytes);
                        bytes = 0;
                    }

                    // remember the byte position of this accept
                    bytes_after_last_accept = bytes;
                    undumped_chars = 0;
                    break;
                }

                case UTF8_REJECT:  // decode found invalid UTF-8 byte
                {
                    switch (error_handler)
                    {
                        case error_handler_t::strict:
                        {
                            std::string sn(3, '\0');
                            snprintf(&sn[0], sn.size(), "%.2X", byte);
                            JSON_THROW(type_error::create(316, "invalid UTF-8 byte at index " + std::to_string(i) + ": 0x" + sn));
                        }

                        case error_handler_t::ignore:
                        case error_handler_t::replace:
                        {
                            // in case we saw this character the first time, we
                            // would like to read it again, because the byte
                            // may be OK for itself, but just not OK for the
                            // previous sequence
                            if (undumped_chars > 0)
                            {
                                --i;
                            }

                            // reset length buffer to the last accepted index;
                            // thus removing/ignoring the invalid characters
                            bytes = bytes_after_last_accept;

                            if (error_handler == error_handler_t::replace)
                            {
                                // add a replacement character
                                if (ensure_ascii)
                                {
                                    string_buffer[bytes++] = '\\';
                                    string_buffer[bytes++] = 'u';
                                    string_buffer[bytes++] = 'f';
                                    string_buffer[bytes++] = 'f';
                                    string_buffer[bytes++] = 'f';
                                    string_buffer[bytes++] = 'd';
                                }
                                else