Assumes that socket_mutex_ is locked and that there are no requests in flight

@brief returns a const reverse iterator to the last element @sa https://json.nlohmann.me/api/basic_json/crbegin/

@brief returns a const reverse iterator to one before the first @sa https://json.nlohmann.me/api/basic_json/crend/

! @brief dump a floating-point number Dump a given floating-point number to output stream @a o. Works internally with @a number_buffer.

! For n != 0, returns k, such that pow10 := 10^(k-1) <= n < 10^k. For n == 0, returns 1 and sets pow10 := 1. */

Parse vocabulary.

! For a normalized diyfp w = f * 2^e, this function returns a (normalized) cached power-of-ten c = f_c * 2^e_c, such that the exponent of the product

! Generates V = buffer * 10^decimal_exponent, such that M- <= V <= M+. M- and M+ must be normalized and share the same exponent -60 <= e <= -32. */