Inside Bitcoin

251{
252    std::ostringstream oss;
253    oss.imbue(std::locale::classic());
254    oss << t;
255    return oss.str();
256}
257
258/**
259 * Check whether a container begins with the given prefix.
260 */
261template <typename T1, size_t PREFIX_LEN>
262[[nodiscard]] inline bool HasPrefix(const T1& obj,
263                                const std::array<uint8_t, PREFIX_LEN>& prefix)
264{
265    return obj.size() >= PREFIX_LEN &&
266           std::equal(std::begin(prefix), std::end(prefix), std::begin(obj));
267}
268
269class LineReader
270{
271    const std::string_view m_str;
272    const size_t m_max_line_length;
273    std::string_view::iterator m_it;
274
275public:
276    explicit LineReader(std::string_view str LIFETIMEBOUND, size_t max_line_length);
277
278    /**
279     * Returns a string from current iterator position up to (but not including) next \n
280     * and advances iterator to the character following the \n on success.
281     * Will not return a line longer than max_line_length.
282     * @returns the next string from the buffer.
283     *          std::nullopt if end of buffer is reached without finding a \n.
284     * @throws a std::runtime_error if max_line_length + 1 bytes are read without finding \n.
285     */
286    std::optional<std::string_view> ReadLine() LIFETIMEBOUND;
287
288    /**
289     * Returns string from current iterator position of specified length
290     * if possible and advances iterator on success.
291     * May exceed max_line_length but will not read past end of buffer.
292     * @param[in]   len     The number of bytes to read from the buffer
293     * @returns a string of the expected length.
294     * @throws a std::runtime_error if there is not enough data in the buffer.
295     */
296    std::string_view ReadLength(size_t len) LIFETIMEBOUND;
297
298    /**
299     * Returns remaining size of bytes in buffer
300     */
301    size_t Remaining() const;
302
303    /**
304     * Returns number of bytes already read from buffer
305     */
306    size_t Consumed() const;
307};
308} // namespace util
309
310#endif // BITCOIN_UTIL_STRING_H
311