From 8585d35c924f3a14e596af46da50688637f9ddf0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Th=C3=A9o=20DELRIEU?= Date: Sun, 9 Jul 2017 17:43:59 +0200 Subject: [PATCH] move serializer outside of basic_json --- src/json.hpp | 1191 +++++++++++++++++++++++++------------------------- 1 file changed, 599 insertions(+), 592 deletions(-) diff --git a/src/json.hpp b/src/json.hpp index d3f35710..39db611c 100644 --- a/src/json.hpp +++ b/src/json.hpp @@ -6378,6 +6378,601 @@ class binary_writer /// the output output_adapter_t oa = nullptr; }; + +/////////////////// +// serialization // +/////////////////// + +template +class serializer +{ + using string_t = typename BasicJsonType::string_t; + using number_float_t = typename BasicJsonType::number_float_t; + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + public: + /*! + @param[in] s output stream to serialize to + @param[in] ichar indentation character to use + */ + serializer(output_adapter_t s, const char ichar) + : o(s), loc(std::localeconv()), + thousands_sep(!loc->thousands_sep ? '\0' : loc->thousands_sep[0]), + decimal_point(!loc->decimal_point ? '\0' : loc->decimal_point[0]), + indent_char(ichar), indent_string(512, indent_char) {} + + // delete because of pointer members + serializer(const serializer&) = delete; + serializer& operator=(const serializer&) = delete; + + /*! + @brief internal implementation of the serialization function + + This function is called by the public member function dump and + organizes the serialization internally. The indentation level is + propagated as additional parameter. In case of arrays and objects, the + function is called recursively. + + - strings and object keys are escaped using `escape_string()` + - integer numbers are converted implicitly via `operator<<` + - floating-point numbers are converted to a string using `"%g"` format + + @param[in] val value to serialize + @param[in] pretty_print whether the output shall be pretty-printed + @param[in] indent_step the indent level + @param[in] current_indent the current indent level (only used internally) + */ + void dump(const BasicJsonType& val, const bool pretty_print, + const unsigned int indent_step, + const unsigned int current_indent = 0) + { + switch (val.m_type) + { + case value_t::object: + { + if (val.m_value.object->empty()) + { + o->write_characters("{}", 2); + return; + } + + if (pretty_print) + { + o->write_characters("{\n", 2); + + // variable to hold indentation for recursive calls + const auto new_indent = current_indent + indent_step; + if (JSON_UNLIKELY(indent_string.size() < new_indent)) + { + indent_string.resize(indent_string.size() * 2, ' '); + } + + // first n-1 elements + auto i = val.m_value.object->cbegin(); + for (size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) + { + o->write_characters(indent_string.c_str(), new_indent); + o->write_character('\"'); + dump_escaped(i->first); + o->write_characters("\": ", 3); + dump(i->second, true, indent_step, new_indent); + o->write_characters(",\n", 2); + } + + // last element + assert(i != val.m_value.object->cend()); + o->write_characters(indent_string.c_str(), new_indent); + o->write_character('\"'); + dump_escaped(i->first); + o->write_characters("\": ", 3); + dump(i->second, true, indent_step, new_indent); + + o->write_character('\n'); + o->write_characters(indent_string.c_str(), current_indent); + o->write_character('}'); + } + else + { + o->write_character('{'); + + // first n-1 elements + auto i = val.m_value.object->cbegin(); + for (size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) + { + o->write_character('\"'); + dump_escaped(i->first); + o->write_characters("\":", 2); + dump(i->second, false, indent_step, current_indent); + o->write_character(','); + } + + // last element + assert(i != val.m_value.object->cend()); + o->write_character('\"'); + dump_escaped(i->first); + o->write_characters("\":", 2); + dump(i->second, false, indent_step, current_indent); + + o->write_character('}'); + } + + return; + } + + case value_t::array: + { + if (val.m_value.array->empty()) + { + o->write_characters("[]", 2); + return; + } + + if (pretty_print) + { + o->write_characters("[\n", 2); + + // variable to hold indentation for recursive calls + const auto new_indent = current_indent + indent_step; + if (indent_string.size() < new_indent) + { + indent_string.resize(new_indent, ' '); + } + + // first n-1 elements + for (auto i = val.m_value.array->cbegin(); + i != val.m_value.array->cend() - 1; ++i) + { + o->write_characters(indent_string.c_str(), new_indent); + dump(*i, true, indent_step, new_indent); + o->write_characters(",\n", 2); + } + + // last element + assert(not val.m_value.array->empty()); + o->write_characters(indent_string.c_str(), new_indent); + dump(val.m_value.array->back(), true, indent_step, new_indent); + + o->write_character('\n'); + o->write_characters(indent_string.c_str(), current_indent); + o->write_character(']'); + } + else + { + o->write_character('['); + + // first n-1 elements + for (auto i = val.m_value.array->cbegin(); + i != val.m_value.array->cend() - 1; ++i) + { + dump(*i, false, indent_step, current_indent); + o->write_character(','); + } + + // last element + assert(not val.m_value.array->empty()); + dump(val.m_value.array->back(), false, indent_step, current_indent); + + o->write_character(']'); + } + + return; + } + + case value_t::string: + { + o->write_character('\"'); + dump_escaped(*val.m_value.string); + o->write_character('\"'); + return; + } + + case value_t::boolean: + { + if (val.m_value.boolean) + { + o->write_characters("true", 4); + } + else + { + o->write_characters("false", 5); + } + return; + } + + case value_t::number_integer: + { + dump_integer(val.m_value.number_integer); + return; + } + + case value_t::number_unsigned: + { + dump_integer(val.m_value.number_unsigned); + return; + } + + case value_t::number_float: + { + dump_float(val.m_value.number_float); + return; + } + + case value_t::discarded: + { + o->write_characters("", 11); + return; + } + + case value_t::null: + { + o->write_characters("null", 4); + return; + } + } + } + + private: + /*! + @brief calculates the extra space to escape a JSON string + + @param[in] s the string to escape + @return the number of characters required to escape string @a s + + @complexity Linear in the length of string @a s. + */ + static std::size_t extra_space(const string_t& s) noexcept + { + return std::accumulate(s.begin(), s.end(), size_t{}, + [](size_t res, typename string_t::value_type c) + { + switch (c) + { + case '"': + case '\\': + case '\b': + case '\f': + case '\n': + case '\r': + case '\t': + { + // from c (1 byte) to \x (2 bytes) + return res + 1; + } + + case 0x00: + case 0x01: + case 0x02: + case 0x03: + case 0x04: + case 0x05: + case 0x06: + case 0x07: + case 0x0b: + case 0x0e: + case 0x0f: + case 0x10: + case 0x11: + case 0x12: + case 0x13: + case 0x14: + case 0x15: + case 0x16: + case 0x17: + case 0x18: + case 0x19: + case 0x1a: + case 0x1b: + case 0x1c: + case 0x1d: + case 0x1e: + case 0x1f: + { + // from c (1 byte) to \uxxxx (6 bytes) + return res + 5; + } + + default: + { + return res; + } + } + }); + } + + /*! + @brief dump escaped string + + Escape a string by replacing certain special characters by a sequence + of an escape character (backslash) and another character and other + control characters by a sequence of "\u" followed by a four-digit hex + representation. The escaped string is written to output stream @a o. + + @param[in] s the string to escape + + @complexity Linear in the length of string @a s. + */ + void dump_escaped(const string_t& s) const + { + const auto space = extra_space(s); + if (space == 0) + { + o->write_characters(s.c_str(), s.size()); + return; + } + + // create a result string of necessary size + string_t result(s.size() + space, '\\'); + std::size_t pos = 0; + + for (const auto& c : s) + { + switch (c) + { + // quotation mark (0x22) + case '"': + { + result[pos + 1] = '"'; + pos += 2; + break; + } + + // reverse solidus (0x5c) + case '\\': + { + // nothing to change + pos += 2; + break; + } + + // backspace (0x08) + case '\b': + { + result[pos + 1] = 'b'; + pos += 2; + break; + } + + // formfeed (0x0c) + case '\f': + { + result[pos + 1] = 'f'; + pos += 2; + break; + } + + // newline (0x0a) + case '\n': + { + result[pos + 1] = 'n'; + pos += 2; + break; + } + + // carriage return (0x0d) + case '\r': + { + result[pos + 1] = 'r'; + pos += 2; + break; + } + + // horizontal tab (0x09) + case '\t': + { + result[pos + 1] = 't'; + pos += 2; + break; + } + + case 0x00: + case 0x01: + case 0x02: + case 0x03: + case 0x04: + case 0x05: + case 0x06: + case 0x07: + case 0x0b: + case 0x0e: + case 0x0f: + case 0x10: + case 0x11: + case 0x12: + case 0x13: + case 0x14: + case 0x15: + case 0x16: + case 0x17: + case 0x18: + case 0x19: + case 0x1a: + case 0x1b: + case 0x1c: + case 0x1d: + case 0x1e: + case 0x1f: + { + // convert a number 0..15 to its hex representation + // (0..f) + static const char hexify[16] = {'0', '1', '2', '3', '4', '5', '6', '7', + '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' + }; + + // print character c as \uxxxx + for (const char m : + {'u', '0', '0', hexify[c >> 4], hexify[c & 0x0f] + }) + { + result[++pos] = m; + } + + ++pos; + break; + } + + default: + { + // all other characters are added as-is + result[pos++] = c; + break; + } + } + } + + assert(pos == s.size() + space); + o->write_characters(result.c_str(), result.size()); + } + + /*! + @brief dump an integer + + Dump a given integer to output stream @a o. Works internally with + @a number_buffer. + + @param[in] x integer number (signed or unsigned) to dump + @tparam NumberType either @a number_integer_t or @a number_unsigned_t + */ + template < + typename NumberType, + detail::enable_if_t::value or + std::is_same::value, + int> = 0 > + void dump_integer(NumberType x) + { + // special case for "0" + if (x == 0) + { + o->write_character('0'); + return; + } + + const bool is_negative = x < 0; + size_t i = 0; + + // spare 1 byte for '\0' + while (x != 0 and i < number_buffer.size() - 1) + { + const auto digit = std::labs(static_cast(x % 10)); + number_buffer[i++] = static_cast('0' + digit); + x /= 10; + } + + // make sure the number has been processed completely + assert(x == 0); + + if (is_negative) + { + // make sure there is capacity for the '-' + assert(i < number_buffer.size() - 2); + number_buffer[i++] = '-'; + } + + std::reverse(number_buffer.begin(), number_buffer.begin() + i); + o->write_characters(number_buffer.data(), i); + } + + /*! + @brief dump a floating-point number + + Dump a given floating-point number to output stream @a o. Works + internally with @a number_buffer. + + @param[in] x floating-point number to dump + */ + void dump_float(number_float_t x) + { + // NaN / inf + if (not std::isfinite(x) or std::isnan(x)) + { + o->write_characters("null", 4); + return; + } + + // special case for 0.0 and -0.0 + if (x == 0) + { + if (std::signbit(x)) + { + o->write_characters("-0.0", 4); + } + else + { + o->write_characters("0.0", 3); + } + return; + } + + // get number of digits for a text -> float -> text round-trip + static constexpr auto d = std::numeric_limits::digits10; + + // the actual conversion + std::ptrdiff_t len = + snprintf(number_buffer.data(), number_buffer.size(), "%.*g", d, x); + + // negative value indicates an error + assert(len > 0); + // check if buffer was large enough + assert(static_cast(len) < number_buffer.size()); + + // erase thousands separator + if (thousands_sep != '\0') + { + const auto end = std::remove(number_buffer.begin(), + number_buffer.begin() + len, thousands_sep); + std::fill(end, number_buffer.end(), '\0'); + assert((end - number_buffer.begin()) <= len); + len = (end - number_buffer.begin()); + } + + // convert decimal point to '.' + if (decimal_point != '\0' and decimal_point != '.') + { + for (auto& c : number_buffer) + { + if (c == decimal_point) + { + c = '.'; + break; + } + } + } + + o->write_characters(number_buffer.data(), static_cast(len)); + + // determine if need to append ".0" + const bool value_is_int_like = + std::none_of(number_buffer.begin(), number_buffer.begin() + len + 1, + [](char c) + { + return c == '.' or c == 'e'; + }); + + if (value_is_int_like) + { + o->write_characters(".0", 2); + } + } + + private: + /// the output of the serializer + output_adapter_t o = nullptr; + + /// a (hopefully) large enough character buffer + std::array number_buffer{{}}; + + /// the locale + const std::lconv* loc = nullptr; + /// the locale's thousand separator character + const char thousands_sep = '\0'; + /// the locale's decimal point character + const char decimal_point = '\0'; + + /// the indentation character + const char indent_char; + + /// the indentation string + string_t indent_string; +}; } // namespace detail /// namespace to hold default `to_json` / `from_json` functions @@ -6849,8 +7444,10 @@ class basic_json template friend struct detail::external_constructor; friend ::nlohmann::json_pointer; friend ::nlohmann::detail::parser; + friend ::nlohmann::detail::serializer; template friend class ::nlohmann::detail::iter_impl; + friend ::nlohmann::detail::binary_writer; /// workaround type for MSVC using basic_json_t = NLOHMANN_BASIC_JSON_TPL; @@ -6873,6 +7470,8 @@ class basic_json using binary_reader = ::nlohmann::detail::binary_reader; using binary_writer = ::nlohmann::detail::binary_writer; + using serializer = ::nlohmann::detail::serializer; + public: using value_t = detail::value_t; // forward declarations @@ -12077,598 +12676,6 @@ class basic_json /// @name serialization /// @{ - private: - /*! - @brief wrapper around the serialization functions - */ - class serializer - { - public: - /*! - @param[in] s output stream to serialize to - @param[in] ichar indentation character to use - */ - serializer(output_adapter_t s, const char ichar) - : o(s), loc(std::localeconv()), - thousands_sep(!loc->thousands_sep ? '\0' : loc->thousands_sep[0]), - decimal_point(!loc->decimal_point ? '\0' : loc->decimal_point[0]), - indent_char(ichar), indent_string(512, indent_char) - {} - - // delete because of pointer members - serializer(const serializer&) = delete; - serializer& operator=(const serializer&) = delete; - - /*! - @brief internal implementation of the serialization function - - This function is called by the public member function dump and - organizes the serialization internally. The indentation level is - propagated as additional parameter. In case of arrays and objects, the - function is called recursively. - - - strings and object keys are escaped using `escape_string()` - - integer numbers are converted implicitly via `operator<<` - - floating-point numbers are converted to a string using `"%g"` format - - @param[in] val value to serialize - @param[in] pretty_print whether the output shall be pretty-printed - @param[in] indent_step the indent level - @param[in] current_indent the current indent level (only used internally) - */ - void dump(const basic_json& val, - const bool pretty_print, - const unsigned int indent_step, - const unsigned int current_indent = 0) - { - switch (val.m_type) - { - case value_t::object: - { - if (val.m_value.object->empty()) - { - o->write_characters("{}", 2); - return; - } - - if (pretty_print) - { - o->write_characters("{\n", 2); - - // variable to hold indentation for recursive calls - const auto new_indent = current_indent + indent_step; - if (JSON_UNLIKELY(indent_string.size() < new_indent)) - { - indent_string.resize(indent_string.size() * 2, ' '); - } - - // first n-1 elements - auto i = val.m_value.object->cbegin(); - for (size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) - { - o->write_characters(indent_string.c_str(), new_indent); - o->write_character('\"'); - dump_escaped(i->first); - o->write_characters("\": ", 3); - dump(i->second, true, indent_step, new_indent); - o->write_characters(",\n", 2); - } - - // last element - assert(i != val.m_value.object->cend()); - o->write_characters(indent_string.c_str(), new_indent); - o->write_character('\"'); - dump_escaped(i->first); - o->write_characters("\": ", 3); - dump(i->second, true, indent_step, new_indent); - - o->write_character('\n'); - o->write_characters(indent_string.c_str(), current_indent); - o->write_character('}'); - } - else - { - o->write_character('{'); - - // first n-1 elements - auto i = val.m_value.object->cbegin(); - for (size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) - { - o->write_character('\"'); - dump_escaped(i->first); - o->write_characters("\":", 2); - dump(i->second, false, indent_step, current_indent); - o->write_character(','); - } - - // last element - assert(i != val.m_value.object->cend()); - o->write_character('\"'); - dump_escaped(i->first); - o->write_characters("\":", 2); - dump(i->second, false, indent_step, current_indent); - - o->write_character('}'); - } - - return; - } - - case value_t::array: - { - if (val.m_value.array->empty()) - { - o->write_characters("[]", 2); - return; - } - - if (pretty_print) - { - o->write_characters("[\n", 2); - - // variable to hold indentation for recursive calls - const auto new_indent = current_indent + indent_step; - if (indent_string.size() < new_indent) - { - indent_string.resize(new_indent, ' '); - } - - // first n-1 elements - for (auto i = val.m_value.array->cbegin(); i != val.m_value.array->cend() - 1; ++i) - { - o->write_characters(indent_string.c_str(), new_indent); - dump(*i, true, indent_step, new_indent); - o->write_characters(",\n", 2); - } - - // last element - assert(not val.m_value.array->empty()); - o->write_characters(indent_string.c_str(), new_indent); - dump(val.m_value.array->back(), true, indent_step, new_indent); - - o->write_character('\n'); - o->write_characters(indent_string.c_str(), current_indent); - o->write_character(']'); - } - else - { - o->write_character('['); - - // first n-1 elements - for (auto i = val.m_value.array->cbegin(); i != val.m_value.array->cend() - 1; ++i) - { - dump(*i, false, indent_step, current_indent); - o->write_character(','); - } - - // last element - assert(not val.m_value.array->empty()); - dump(val.m_value.array->back(), false, indent_step, current_indent); - - o->write_character(']'); - } - - return; - } - - case value_t::string: - { - o->write_character('\"'); - dump_escaped(*val.m_value.string); - o->write_character('\"'); - return; - } - - case value_t::boolean: - { - if (val.m_value.boolean) - { - o->write_characters("true", 4); - } - else - { - o->write_characters("false", 5); - } - return; - } - - case value_t::number_integer: - { - dump_integer(val.m_value.number_integer); - return; - } - - case value_t::number_unsigned: - { - dump_integer(val.m_value.number_unsigned); - return; - } - - case value_t::number_float: - { - dump_float(val.m_value.number_float); - return; - } - - case value_t::discarded: - { - o->write_characters("", 11); - return; - } - - case value_t::null: - { - o->write_characters("null", 4); - return; - } - } - } - - private: - /*! - @brief calculates the extra space to escape a JSON string - - @param[in] s the string to escape - @return the number of characters required to escape string @a s - - @complexity Linear in the length of string @a s. - */ - static std::size_t extra_space(const string_t& s) noexcept - { - return std::accumulate(s.begin(), s.end(), size_t{}, - [](size_t res, typename string_t::value_type c) - { - switch (c) - { - case '"': - case '\\': - case '\b': - case '\f': - case '\n': - case '\r': - case '\t': - { - // from c (1 byte) to \x (2 bytes) - return res + 1; - } - - case 0x00: - case 0x01: - case 0x02: - case 0x03: - case 0x04: - case 0x05: - case 0x06: - case 0x07: - case 0x0b: - case 0x0e: - case 0x0f: - case 0x10: - case 0x11: - case 0x12: - case 0x13: - case 0x14: - case 0x15: - case 0x16: - case 0x17: - case 0x18: - case 0x19: - case 0x1a: - case 0x1b: - case 0x1c: - case 0x1d: - case 0x1e: - case 0x1f: - { - // from c (1 byte) to \uxxxx (6 bytes) - return res + 5; - } - - default: - { - return res; - } - } - }); - } - - /*! - @brief dump escaped string - - Escape a string by replacing certain special characters by a sequence - of an escape character (backslash) and another character and other - control characters by a sequence of "\u" followed by a four-digit hex - representation. The escaped string is written to output stream @a o. - - @param[in] s the string to escape - - @complexity Linear in the length of string @a s. - */ - void dump_escaped(const string_t& s) const - { - const auto space = extra_space(s); - if (space == 0) - { - o->write_characters(s.c_str(), s.size()); - return; - } - - // create a result string of necessary size - string_t result(s.size() + space, '\\'); - std::size_t pos = 0; - - for (const auto& c : s) - { - switch (c) - { - // quotation mark (0x22) - case '"': - { - result[pos + 1] = '"'; - pos += 2; - break; - } - - // reverse solidus (0x5c) - case '\\': - { - // nothing to change - pos += 2; - break; - } - - // backspace (0x08) - case '\b': - { - result[pos + 1] = 'b'; - pos += 2; - break; - } - - // formfeed (0x0c) - case '\f': - { - result[pos + 1] = 'f'; - pos += 2; - break; - } - - // newline (0x0a) - case '\n': - { - result[pos + 1] = 'n'; - pos += 2; - break; - } - - // carriage return (0x0d) - case '\r': - { - result[pos + 1] = 'r'; - pos += 2; - break; - } - - // horizontal tab (0x09) - case '\t': - { - result[pos + 1] = 't'; - pos += 2; - break; - } - - case 0x00: - case 0x01: - case 0x02: - case 0x03: - case 0x04: - case 0x05: - case 0x06: - case 0x07: - case 0x0b: - case 0x0e: - case 0x0f: - case 0x10: - case 0x11: - case 0x12: - case 0x13: - case 0x14: - case 0x15: - case 0x16: - case 0x17: - case 0x18: - case 0x19: - case 0x1a: - case 0x1b: - case 0x1c: - case 0x1d: - case 0x1e: - case 0x1f: - { - // convert a number 0..15 to its hex representation - // (0..f) - static const char hexify[16] = - { - '0', '1', '2', '3', '4', '5', '6', '7', - '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' - }; - - // print character c as \uxxxx - for (const char m : - { 'u', '0', '0', hexify[c >> 4], hexify[c & 0x0f] - }) - { - result[++pos] = m; - } - - ++pos; - break; - } - - default: - { - // all other characters are added as-is - result[pos++] = c; - break; - } - } - } - - assert(pos == s.size() + space); - o->write_characters(result.c_str(), result.size()); - } - - /*! - @brief dump an integer - - Dump a given integer to output stream @a o. Works internally with - @a number_buffer. - - @param[in] x integer number (signed or unsigned) to dump - @tparam NumberType either @a number_integer_t or @a number_unsigned_t - */ - template::value or - std::is_same::value, int> = 0> - void dump_integer(NumberType x) - { - // special case for "0" - if (x == 0) - { - o->write_character('0'); - return; - } - - const bool is_negative = x < 0; - size_t i = 0; - - // spare 1 byte for '\0' - while (x != 0 and i < number_buffer.size() - 1) - { - const auto digit = std::labs(static_cast(x % 10)); - number_buffer[i++] = static_cast('0' + digit); - x /= 10; - } - - // make sure the number has been processed completely - assert(x == 0); - - if (is_negative) - { - // make sure there is capacity for the '-' - assert(i < number_buffer.size() - 2); - number_buffer[i++] = '-'; - } - - std::reverse(number_buffer.begin(), number_buffer.begin() + i); - o->write_characters(number_buffer.data(), i); - } - - /*! - @brief dump a floating-point number - - Dump a given floating-point number to output stream @a o. Works - internally with @a number_buffer. - - @param[in] x floating-point number to dump - */ - void dump_float(number_float_t x) - { - // NaN / inf - if (not std::isfinite(x) or std::isnan(x)) - { - o->write_characters("null", 4); - return; - } - - // special case for 0.0 and -0.0 - if (x == 0) - { - if (std::signbit(x)) - { - o->write_characters("-0.0", 4); - } - else - { - o->write_characters("0.0", 3); - } - return; - } - - // get number of digits for a text -> float -> text round-trip - static constexpr auto d = std::numeric_limits::digits10; - - // the actual conversion - std::ptrdiff_t len = snprintf(number_buffer.data(), number_buffer.size(), - "%.*g", d, x); - - // negative value indicates an error - assert(len > 0); - // check if buffer was large enough - assert(static_cast(len) < number_buffer.size()); - - // erase thousands separator - if (thousands_sep != '\0') - { - const auto end = std::remove(number_buffer.begin(), - number_buffer.begin() + len, - thousands_sep); - std::fill(end, number_buffer.end(), '\0'); - assert((end - number_buffer.begin()) <= len); - len = (end - number_buffer.begin()); - } - - // convert decimal point to '.' - if (decimal_point != '\0' and decimal_point != '.') - { - for (auto& c : number_buffer) - { - if (c == decimal_point) - { - c = '.'; - break; - } - } - } - - o->write_characters(number_buffer.data(), static_cast(len)); - - // determine if need to append ".0" - const bool value_is_int_like = std::none_of(number_buffer.begin(), - number_buffer.begin() + len + 1, - [](char c) - { - return c == '.' or c == 'e'; - }); - - if (value_is_int_like) - { - o->write_characters(".0", 2); - } - } - - private: - /// the output of the serializer - output_adapter_t o = nullptr; - - /// a (hopefully) large enough character buffer - std::array number_buffer{{}}; - - /// the locale - const std::lconv* loc = nullptr; - /// the locale's thousand separator character - const char thousands_sep = '\0'; - /// the locale's decimal point character - const char decimal_point = '\0'; - - /// the indentation character - const char indent_char; - - /// the indentation string - string_t indent_string; - }; - - public: /*! @brief serialize to stream