void copy(Output_Stream &output) {
char buffer[256 * 1024];
size_t number_bytes_read;
while ((number_bytes_read = read(buffer, sizeof(buffer))) > 0) {
output.write(buffer, number_bytes_read);
}
}
void operator()(Input_Stream &input, Output_Stream &output,
const rstd::vector<rel::rlang::token> &tokens) {
NP1_ASSERT(tokens.size() == 0, "rel.record_count accepts no arguments");
// Read & discard the headings.
input.parse_headings();
uint64_t number_records = 0;
input.parse_records(record_counter_callback(number_records));
output.write(str::to_dec_str(number_records).c_str());
}