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Univerxel/deps/toml++/toml_print_to_stream.h

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C++

//# This file is a part of toml++ and is subject to the the terms of the MIT license.
//# Copyright (c) 2019-2020 Mark Gillard <mark.gillard@outlook.com.au>
//# See https://github.com/marzer/tomlplusplus/blob/master/LICENSE for the full license text.
// SPDX-License-Identifier: MIT
#pragma once
#include "toml_date_time.h"
TOML_DISABLE_WARNINGS
#include <cmath>
#if TOML_INT_CHARCONV || TOML_FLOAT_CHARCONV
#include <charconv>
#endif
#if !TOML_INT_CHARCONV || !TOML_FLOAT_CHARCONV
#include <sstream>
#endif
#if !TOML_INT_CHARCONV
#include <iomanip>
#endif
TOML_ENABLE_WARNINGS
TOML_PUSH_WARNINGS
TOML_DISABLE_SWITCH_WARNINGS
TOML_IMPL_NAMESPACE_START
{
// Q: "why does print_to_stream() exist? why not just use ostream::write(), ostream::put() etc?"
// A: - I'm supporting C++20's char8_t as well; wrapping streams allows switching string modes transparently.
// - I'm using <charconv> to format numerics. Faster and locale-independent.
// - I can avoid forcing users to drag in <sstream> and <iomanip>.
// Q: "there's a bit of reinterpret_casting here, is any of it UB?"
// A: - If the source string data is char and the output string is char8_t, then technically yes,
// but not in the other direction. I test in both modes on Clang, GCC and MSVC and have yet to
// see it actually causing an issue, but in the event it does present a problem it's not going to
// be a show-stopper since all it means is I need to do duplicate some code.
// - Strings in C++. Honestly.
template <typename Char1, typename Char2>
inline void print_to_stream(std::basic_string_view<Char1> str, std::basic_ostream<Char2>& stream)
{
static_assert(sizeof(Char1) == 1);
static_assert(sizeof(Char2) == 1);
stream.write(reinterpret_cast<const Char2*>(str.data()), static_cast<std::streamsize>(str.length()));
}
template <typename Char1, typename Char2>
inline void print_to_stream(const std::basic_string<Char1>& str, std::basic_ostream<Char2>& stream)
{
static_assert(sizeof(Char1) == 1);
static_assert(sizeof(Char2) == 1);
stream.write(reinterpret_cast<const Char2*>(str.data()), static_cast<std::streamsize>(str.length()));
}
template <typename Char>
inline void print_to_stream(char character, std::basic_ostream<Char>& stream)
{
static_assert(sizeof(Char) == 1);
stream.put(static_cast<Char>(character));
}
template <typename Char>
TOML_ATTR(nonnull)
inline void print_to_stream(const char* str, size_t len, std::basic_ostream<Char>& stream)
{
static_assert(sizeof(Char) == 1);
stream.write(reinterpret_cast<const Char*>(str), static_cast<std::streamsize>(len));
}
#ifdef __cpp_lib_char8_t
template <typename Char>
inline void print_to_stream(char8_t character, std::basic_ostream<Char>& stream)
{
static_assert(sizeof(Char) == 1);
stream.put(static_cast<Char>(character));
}
template <typename Char>
TOML_ATTR(nonnull)
inline void print_to_stream(const char8_t* str, size_t len, std::basic_ostream<Char>& stream)
{
static_assert(sizeof(Char) == 1);
stream.write(reinterpret_cast<const Char*>(str), static_cast<std::streamsize>(len));
}
#endif
template <typename T> inline constexpr size_t charconv_buffer_length = 0;
template <> inline constexpr size_t charconv_buffer_length<double> = 60;
template <> inline constexpr size_t charconv_buffer_length<float> = 40;
template <> inline constexpr size_t charconv_buffer_length<uint64_t> = 20; // strlen("18446744073709551615")
template <> inline constexpr size_t charconv_buffer_length<int64_t> = 20; // strlen("-9223372036854775808")
template <> inline constexpr size_t charconv_buffer_length<int32_t> = 11; // strlen("-2147483648")
template <> inline constexpr size_t charconv_buffer_length<int16_t> = 6; // strlen("-32768")
template <> inline constexpr size_t charconv_buffer_length<int8_t> = 4; // strlen("-128")
template <> inline constexpr size_t charconv_buffer_length<uint32_t> = 10; // strlen("4294967295")
template <> inline constexpr size_t charconv_buffer_length<uint16_t> = 5; // strlen("65535")
template <> inline constexpr size_t charconv_buffer_length<uint8_t> = 3; // strlen("255")
template <typename T, typename Char>
inline void print_integer_to_stream(T val, std::basic_ostream<Char>& stream, value_flags format = {})
{
static_assert(
sizeof(Char) == 1,
"The stream's underlying character type must be 1 byte in size."
);
if (!val)
{
print_to_stream('0', stream);
return;
}
int base = 10;
if (format != value_flags::none && val >= T{})
{
switch (format)
{
case value_flags::format_as_binary: base = 2; break;
case value_flags::format_as_octal: base = 8; break;
case value_flags::format_as_hexadecimal: base = 16; break;
default: break;
}
}
#if TOML_INT_CHARCONV
{
char buf[(sizeof(T) * CHAR_BIT)];
const auto res = std::to_chars(buf, buf + sizeof(buf), val, base);
const auto len = static_cast<size_t>(res.ptr - buf);
if (base == 16)
{
for (size_t i = 0; i < len; i++)
if (buf[i] >= 'a')
buf[i] -= 32;
}
print_to_stream(buf, len, stream);
}
#else
{
using unsigned_type = std::conditional_t<(sizeof(T) > sizeof(unsigned)), std::make_unsigned_t<T>, unsigned>;
using cast_type = std::conditional_t<std::is_signed_v<T>, std::make_signed_t<unsigned_type>, unsigned_type>;
if TOML_UNLIKELY(format == value_flags::format_as_binary)
{
bool found_one = false;
const auto v = static_cast<unsigned_type>(val);
unsigned_type mask = unsigned_type{ 1 } << (sizeof(unsigned_type) * CHAR_BIT - 1u);
for (unsigned i = 0; i < sizeof(unsigned_type) * CHAR_BIT; i++)
{
if ((v & mask))
{
print_to_stream('1', stream);
found_one = true;
}
else if (found_one)
print_to_stream('0', stream);
mask >>= 1;
}
}
else
{
std::ostringstream ss;
ss.imbue(std::locale::classic());
ss << std::uppercase << std::setbase(base);
ss << static_cast<cast_type>(val);
const auto str = std::move(ss).str();
print_to_stream(str, stream);
}
}
#endif
}
#define TOML_P2S_OVERLOAD(Type) \
template <typename Char> \
inline void print_to_stream(Type val, std::basic_ostream<Char>& stream, value_flags format) \
{ \
static_assert(sizeof(Char) == 1); \
print_integer_to_stream(val, stream, format); \
}
TOML_P2S_OVERLOAD(int8_t)
TOML_P2S_OVERLOAD(int16_t)
TOML_P2S_OVERLOAD(int32_t)
TOML_P2S_OVERLOAD(int64_t)
TOML_P2S_OVERLOAD(uint8_t)
TOML_P2S_OVERLOAD(uint16_t)
TOML_P2S_OVERLOAD(uint32_t)
TOML_P2S_OVERLOAD(uint64_t)
#undef TOML_P2S_OVERLOAD
template <typename T, typename Char>
inline void print_floating_point_to_stream(T val, std::basic_ostream<Char>& stream, bool hexfloat = false)
{
static_assert(
sizeof(Char) == 1,
"The stream's underlying character type must be 1 byte in size."
);
switch (impl::fpclassify(val))
{
case fp_class::neg_inf:
print_to_stream("-inf"sv, stream);
break;
case fp_class::pos_inf:
print_to_stream("inf"sv, stream);
break;
case fp_class::nan:
print_to_stream("nan"sv, stream);
break;
case fp_class::ok:
{
static constexpr auto needs_decimal_point = [](auto&& s) noexcept
{
for (auto c : s)
if (c == '.' || c == 'E' || c == 'e')
return false;
return true;
};
#if TOML_FLOAT_CHARCONV
{
char buf[charconv_buffer_length<T>];
const auto res = hexfloat
? std::to_chars(buf, buf + sizeof(buf), val, std::chars_format::hex)
: std::to_chars(buf, buf + sizeof(buf), val);
const auto str = std::string_view{ buf, static_cast<size_t>(res.ptr - buf) };
print_to_stream(str, stream);
if (!hexfloat && needs_decimal_point(str))
print_to_stream(".0"sv, stream);
}
#else
{
std::ostringstream ss;
ss.imbue(std::locale::classic());
ss.precision(std::numeric_limits<T>::digits10 + 1);
if (hexfloat)
ss << std::hexfloat;
ss << val;
const auto str = std::move(ss).str();
print_to_stream(str, stream);
if (!hexfloat && needs_decimal_point(str))
print_to_stream(".0"sv, stream);
}
#endif
break;
}
TOML_NO_DEFAULT_CASE;
}
}
#if !defined(DOXYGEN) && !TOML_HEADER_ONLY
extern template TOML_API void print_floating_point_to_stream(double, std::ostream&, bool);
#endif
#define TOML_P2S_OVERLOAD(Type) \
template <typename Char> \
inline void print_to_stream(Type val, std::basic_ostream<Char>& stream) \
{ \
static_assert(sizeof(Char) == 1); \
print_floating_point_to_stream(val, stream); \
}
TOML_P2S_OVERLOAD(double)
#undef TOML_P2S_OVERLOAD
template <typename Char>
inline void print_to_stream(bool val, std::basic_ostream<Char>& stream)
{
static_assert(sizeof(Char) == 1);
print_to_stream(val ? "true"sv : "false"sv, stream);
}
template <typename T, typename Char>
inline void print_to_stream(T val, std::basic_ostream<Char>& stream, size_t zero_pad_to_digits)
{
static_assert(sizeof(Char) == 1);
#if TOML_INT_CHARCONV
char buf[charconv_buffer_length<T>];
const auto res = std::to_chars(buf, buf + sizeof(buf), val);
const auto len = static_cast<size_t>(res.ptr - buf);
for (size_t i = len; i < zero_pad_to_digits; i++)
print_to_stream('0', stream);
print_to_stream(buf, static_cast<size_t>(res.ptr - buf), stream);
#else
std::ostringstream ss;
ss.imbue(std::locale::classic());
using cast_type = std::conditional_t<std::is_signed_v<T>, int64_t, uint64_t>;
ss << std::setfill('0') << std::setw(static_cast<int>(zero_pad_to_digits)) << static_cast<cast_type>(val);
const auto str = std::move(ss).str();
print_to_stream(str, stream);
#endif
}
template <typename Char>
inline void print_to_stream(const toml::date& val, std::basic_ostream<Char>& stream)
{
static_assert(sizeof(Char) == 1);
print_to_stream(val.year, stream, 4_sz);
print_to_stream('-', stream);
print_to_stream(val.month, stream, 2_sz);
print_to_stream('-', stream);
print_to_stream(val.day, stream, 2_sz);
}
template <typename Char>
inline void print_to_stream(const toml::time& val, std::basic_ostream<Char>& stream)
{
static_assert(sizeof(Char) == 1);
print_to_stream(val.hour, stream, 2_sz);
print_to_stream(':', stream);
print_to_stream(val.minute, stream, 2_sz);
print_to_stream(':', stream);
print_to_stream(val.second, stream, 2_sz);
if (val.nanosecond && val.nanosecond <= 999999999u)
{
print_to_stream('.', stream);
auto ns = val.nanosecond;
size_t digits = 9_sz;
while (ns % 10u == 0u)
{
ns /= 10u;
digits--;
}
print_to_stream(ns, stream, digits);
}
}
template <typename Char>
inline void print_to_stream(toml::time_offset val, std::basic_ostream<Char>& stream)
{
static_assert(sizeof(Char) == 1);
if (!val.minutes)
print_to_stream('Z', stream);
else
{
auto mins = static_cast<int>(val.minutes);
if (mins < 0)
{
print_to_stream('-', stream);
mins = -mins;
}
else
print_to_stream('+', stream);
const auto hours = mins / 60;
if (hours)
{
print_to_stream(static_cast<unsigned int>(hours), stream, 2_sz);
mins -= hours * 60;
}
else
print_to_stream("00"sv, stream);
print_to_stream(':', stream);
print_to_stream(static_cast<unsigned int>(mins), stream, 2_sz);
}
}
template <typename Char>
inline void print_to_stream(const toml::date_time& val, std::basic_ostream<Char>& stream)
{
static_assert(sizeof(Char) == 1);
print_to_stream(val.date, stream);
print_to_stream('T', stream);
print_to_stream(val.time, stream);
if (val.offset)
print_to_stream(*val.offset, stream);
}
TOML_PUSH_WARNINGS
TOML_DISABLE_ARITHMETIC_WARNINGS
template <typename T, typename Char>
void print_to_stream_with_escapes(T && str, std::basic_ostream<Char>& stream)
{
static_assert(sizeof(Char) == 1);
for (auto c : str)
{
if TOML_UNLIKELY(c >= '\x00' && c <= '\x1F')
print_to_stream(low_character_escape_table[c], stream);
else if TOML_UNLIKELY(c == '\x7F')
print_to_stream("\\u007F"sv, stream);
else if TOML_UNLIKELY(c == '"')
print_to_stream("\\\""sv, stream);
else if TOML_UNLIKELY(c == '\\')
print_to_stream("\\\\"sv, stream);
else
print_to_stream(c, stream);
}
}
TOML_POP_WARNINGS // TOML_DISABLE_ARITHMETIC_WARNINGS
}
TOML_IMPL_NAMESPACE_END
TOML_NAMESPACE_START
{
/// \brief Prints a source_position to a stream.
///
/// \detail \cpp
/// auto tbl = toml::parse("bar = 42"sv);
///
/// std::cout << "The value for 'bar' was found on "sv
/// << tbl.get("bar")->source().begin()
/// << "\n";
///
/// \ecpp
///
/// \out
/// The value for 'bar' was found on line 1, column 7
/// \eout
///
/// \tparam Char The output stream's underlying character type. Must be 1 byte in size.
/// \param lhs The stream.
/// \param rhs The source_position.
///
/// \returns The input stream.
template <typename Char>
inline std::basic_ostream<Char>& operator << (std::basic_ostream<Char>& lhs, const source_position& rhs)
{
static_assert(
sizeof(Char) == 1,
"The stream's underlying character type must be 1 byte in size."
);
impl::print_to_stream("line "sv, lhs);
impl::print_to_stream(rhs.line, lhs);
impl::print_to_stream(", column "sv, lhs);
impl::print_to_stream(rhs.column, lhs);
return lhs;
}
/// \brief Prints a source_region to a stream.
///
/// \detail \cpp
/// auto tbl = toml::parse("bar = 42", "config.toml");
///
/// std::cout << "The value for 'bar' was found on "sv
/// << tbl.get("bar")->source()
/// << "\n";
///
/// \ecpp
///
/// \out
/// The value for 'bar' was found on line 1, column 7 of 'config.toml'
/// \eout
///
/// \tparam Char The output stream's underlying character type. Must be 1 byte in size.
/// \param lhs The stream.
/// \param rhs The source_position.
///
/// \returns The input stream.
template <typename Char>
inline std::basic_ostream<Char>& operator << (std::basic_ostream<Char>& lhs, const source_region& rhs)
{
static_assert(
sizeof(Char) == 1,
"The stream's underlying character type must be 1 byte in size."
);
lhs << rhs.begin;
if (rhs.path)
{
impl::print_to_stream(" of '"sv, lhs);
impl::print_to_stream(*rhs.path, lhs);
impl::print_to_stream('\'', lhs);
}
return lhs;
}
#if !defined(DOXYGEN) && !TOML_HEADER_ONLY
extern template TOML_API std::ostream& operator << (std::ostream&, const source_position&);
extern template TOML_API std::ostream& operator << (std::ostream&, const source_region&);
#endif
}
TOML_NAMESPACE_END
TOML_POP_WARNINGS // TOML_DISABLE_SWITCH_WARNINGS