tomlplusplus/include/toml++/toml_print_to_stream.h
Mark Gillard 98c599ec2c removed <cmath> dependency
also:
- fixed some pedantic clang warnings
- added preliminary support for ICC
- documentation fixes
2020-02-29 22:34:08 +02:00

340 lines
11 KiB
C++

#pragma once
#include "toml_date_time.h"
TOML_IMPL_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 lot 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>
TOML_ALWAYS_INLINE
void print_to_stream(std::basic_string_view<CHAR1> str, std::basic_ostream<CHAR2>& stream) TOML_MAY_THROW
{
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>
TOML_ALWAYS_INLINE
void print_to_stream(const std::basic_string<CHAR1>& str, std::basic_ostream<CHAR2>& stream) TOML_MAY_THROW
{
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>
TOML_ALWAYS_INLINE
void print_to_stream(char character, std::basic_ostream<CHAR>& stream) TOML_MAY_THROW
{
static_assert(sizeof(CHAR) == 1);
stream.put(static_cast<CHAR>(character));
}
template <typename CHAR>
TOML_GCC_ATTR(nonnull) TOML_ALWAYS_INLINE
void print_to_stream(const char* str, size_t len, std::basic_ostream<CHAR>& stream) TOML_MAY_THROW
{
static_assert(sizeof(CHAR) == 1);
stream.write(reinterpret_cast<const CHAR*>(str), static_cast<std::streamsize>(len));
}
#if defined(__cpp_lib_char8_t)
template <typename CHAR>
TOML_ALWAYS_INLINE
void print_to_stream(char8_t character, std::basic_ostream<CHAR>& stream) TOML_MAY_THROW
{
static_assert(sizeof(CHAR) == 1);
stream.put(static_cast<CHAR>(character));
}
template <typename CHAR>
TOML_GCC_ATTR(nonnull) TOML_ALWAYS_INLINE
void print_to_stream(const char8_t* str, size_t len, std::basic_ostream<CHAR>& stream) TOML_MAY_THROW
{
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) TOML_MAY_THROW
{
static_assert(
sizeof(CHAR) == 1,
"The stream's underlying character type must be 1 byte in size."
);
TOML_GCC_ATTR(uninitialized) char buf[charconv_buffer_length<T>];
const auto res = std::to_chars(buf, buf + sizeof(buf), val);
print_to_stream(buf, static_cast<size_t>(res.ptr - buf), stream);
}
#define TOML_P2S_OVERLOAD(type) \
template <typename CHAR> \
TOML_ALWAYS_INLINE \
void print_to_stream(type val, std::basic_ostream<CHAR>& stream) TOML_MAY_THROW \
{ \
static_assert(sizeof(CHAR) == 1); \
print_integer_to_stream(val, stream); \
}
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) TOML_MAY_THROW
{
static_assert(
sizeof(CHAR) == 1,
"The stream's underlying character type must be 1 byte in size."
);
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_USE_STREAMS_FOR_FLOATS
{
std::ostringstream oss;
oss.precision(std::numeric_limits<T>::digits10 + 1);
if (hexfloat)
oss << std::hexfloat;
oss << val;
const auto str = oss.str();
print_to_stream(str, stream);
if (needs_decimal_point(str))
print_to_stream(".0"sv, stream);
}
#else
{
TOML_GCC_ATTR(uninitialized) 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 (needs_decimal_point(str))
print_to_stream(".0"sv, stream);
}
#endif
}
#define TOML_P2S_OVERLOAD(type) \
template <typename CHAR> \
TOML_ALWAYS_INLINE \
void print_to_stream(type val, std::basic_ostream<CHAR>& stream) TOML_MAY_THROW \
{ \
static_assert(sizeof(CHAR) == 1); \
print_floating_point_to_stream(val, stream); \
}
TOML_P2S_OVERLOAD(float)
TOML_P2S_OVERLOAD(double)
#undef TOML_P2S_OVERLOAD
template <typename CHAR>
TOML_ALWAYS_INLINE
void print_to_stream(bool val, std::basic_ostream<CHAR>& stream) TOML_MAY_THROW
{
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) TOML_MAY_THROW
{
static_assert(sizeof(CHAR) == 1);
TOML_GCC_ATTR(uninitialized) 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);
}
template <typename CHAR>
inline void print_to_stream(const toml::date& val, std::basic_ostream<CHAR>& stream) TOML_MAY_THROW
{
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) TOML_MAY_THROW
{
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) TOML_MAY_THROW
{
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) TOML_MAY_THROW
{
static_assert(sizeof(CHAR) == 1);
print_to_stream(val.date, stream);
print_to_stream('T', stream);
print_to_stream(val.time, stream);
if (val.time_offset)
print_to_stream(*val.time_offset, stream);
}
TOML_PUSH_WARNINGS
TOML_DISABLE_ALL_WARNINGS
template <typename T, typename CHAR>
void print_to_stream_with_escapes(T && str, std::basic_ostream<CHAR>& stream) TOML_MAY_THROW
{
static_assert(sizeof(CHAR) == 1);
for (auto c : str)
{
if (c >= TOML_STRING_PREFIX('\x00') && c <= TOML_STRING_PREFIX('\x1F')) TOML_UNLIKELY
print_to_stream(low_character_escape_table[c], stream);
else if (c == TOML_STRING_PREFIX('\x7F')) TOML_UNLIKELY
print_to_stream(TOML_STRING_PREFIX("\\u007F"sv), stream);
else if (c == TOML_STRING_PREFIX('"')) TOML_UNLIKELY
print_to_stream(TOML_STRING_PREFIX("\\\""sv), stream);
else if (c == TOML_STRING_PREFIX('\\')) TOML_UNLIKELY
print_to_stream(TOML_STRING_PREFIX("\\\\"sv), stream);
else
print_to_stream(c, stream);
}
}
TOML_POP_WARNINGS
}
TOML_IMPL_END
TOML_START
{
template <typename CHAR>
std::basic_ostream<CHAR>& operator << (std::basic_ostream<CHAR>& lhs, const source_position& rhs)
TOML_MAY_THROW
{
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;
}
template <typename CHAR>
std::basic_ostream<CHAR>& operator << (std::basic_ostream<CHAR>& lhs, const source_region& rhs)
TOML_MAY_THROW
{
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;
}
template <typename CHAR>
std::basic_ostream<CHAR>& operator << (std::basic_ostream<CHAR>& lhs, const parse_error& rhs)
TOML_MAY_THROW
{
impl::print_to_stream(rhs.description(), lhs);
impl::print_to_stream("\n\t(error occurred at "sv, lhs);
lhs << rhs.source();
impl::print_to_stream(")"sv, lhs);
return lhs;
}
}
TOML_END