maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/libcxx/include/charconv

642 lines
20 KiB
C++
Raw Blame History

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP_CHARCONV
#define _LIBCPP_CHARCONV
/*
charconv synopsis
namespace std {
// floating-point format for primitive numerical conversion
enum class chars_format {
scientific = unspecified,
fixed = unspecified,
hex = unspecified,
general = fixed | scientific
};
// 23.20.2, primitive numerical output conversion
struct to_chars_result {
char* ptr;
errc ec;
friend bool operator==(const to_chars_result&, const to_chars_result&) = default; // since C++20
};
to_chars_result to_chars(char* first, char* last, see below value,
int base = 10);
to_chars_result to_chars(char* first, char* last, bool value,
int base = 10) = delete;
to_chars_result to_chars(char* first, char* last, float value);
to_chars_result to_chars(char* first, char* last, double value);
to_chars_result to_chars(char* first, char* last, long double value);
to_chars_result to_chars(char* first, char* last, float value,
chars_format fmt);
to_chars_result to_chars(char* first, char* last, double value,
chars_format fmt);
to_chars_result to_chars(char* first, char* last, long double value,
chars_format fmt);
to_chars_result to_chars(char* first, char* last, float value,
chars_format fmt, int precision);
to_chars_result to_chars(char* first, char* last, double value,
chars_format fmt, int precision);
to_chars_result to_chars(char* first, char* last, long double value,
chars_format fmt, int precision);
// 23.20.3, primitive numerical input conversion
struct from_chars_result {
const char* ptr;
errc ec;
friend bool operator==(const from_chars_result&, const from_chars_result&) = default; // since C++20
};
from_chars_result from_chars(const char* first, const char* last,
see below& value, int base = 10);
from_chars_result from_chars(const char* first, const char* last,
float& value,
chars_format fmt = chars_format::general);
from_chars_result from_chars(const char* first, const char* last,
double& value,
chars_format fmt = chars_format::general);
from_chars_result from_chars(const char* first, const char* last,
long double& value,
chars_format fmt = chars_format::general);
} // namespace std
*/
#include <__assert> // all public C++ headers provide the assertion handler
#include <__availability>
#include <__bits>
#include <__charconv/chars_format.h>
#include <__charconv/from_chars_result.h>
#include <__charconv/to_chars_result.h>
#include <__config>
#include <__debug>
#include <__errc>
#include <__utility/unreachable.h>
#include <cmath> // for log2f
#include <cstdint>
#include <cstdlib>
#include <cstring>
#include <limits>
#include <type_traits>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_PUSH_MACROS
#include <__undef_macros>
_LIBCPP_BEGIN_NAMESPACE_STD
#ifndef _LIBCPP_CXX03_LANG
namespace __itoa {
_LIBCPP_AVAILABILITY_TO_CHARS _LIBCPP_FUNC_VIS char* __u64toa(uint64_t __value, char* __buffer) noexcept;
_LIBCPP_AVAILABILITY_TO_CHARS _LIBCPP_FUNC_VIS char* __u32toa(uint32_t __value, char* __buffer) noexcept;
} // namespace __itoa
to_chars_result to_chars(char*, char*, bool, int = 10) = delete;
from_chars_result from_chars(const char*, const char*, bool, int = 10) = delete;
namespace __itoa
{
static constexpr uint64_t __pow10_64[] = {
UINT64_C(0),
UINT64_C(10),
UINT64_C(100),
UINT64_C(1000),
UINT64_C(10000),
UINT64_C(100000),
UINT64_C(1000000),
UINT64_C(10000000),
UINT64_C(100000000),
UINT64_C(1000000000),
UINT64_C(10000000000),
UINT64_C(100000000000),
UINT64_C(1000000000000),
UINT64_C(10000000000000),
UINT64_C(100000000000000),
UINT64_C(1000000000000000),
UINT64_C(10000000000000000),
UINT64_C(100000000000000000),
UINT64_C(1000000000000000000),
UINT64_C(10000000000000000000),
};
static constexpr uint32_t __pow10_32[] = {
UINT32_C(0), UINT32_C(10), UINT32_C(100),
UINT32_C(1000), UINT32_C(10000), UINT32_C(100000),
UINT32_C(1000000), UINT32_C(10000000), UINT32_C(100000000),
UINT32_C(1000000000),
};
template <typename _Tp, typename = void>
struct _LIBCPP_HIDDEN __traits_base
{
using type = uint64_t;
static _LIBCPP_HIDE_FROM_ABI int __width(_Tp __v)
{
auto __t = (64 - std::__libcpp_clz(static_cast<type>(__v | 1))) * 1233 >> 12;
return __t - (__v < __pow10_64[__t]) + 1;
}
_LIBCPP_AVAILABILITY_TO_CHARS
static _LIBCPP_HIDE_FROM_ABI char* __convert(_Tp __v, char* __p)
{
return __u64toa(__v, __p);
}
static _LIBCPP_HIDE_FROM_ABI decltype(__pow10_64)& __pow() { return __pow10_64; }
};
template <typename _Tp>
struct _LIBCPP_HIDDEN
__traits_base<_Tp, decltype(void(uint32_t{declval<_Tp>()}))>
{
using type = uint32_t;
static _LIBCPP_HIDE_FROM_ABI int __width(_Tp __v)
{
auto __t = (32 - std::__libcpp_clz(static_cast<type>(__v | 1))) * 1233 >> 12;
return __t - (__v < __pow10_32[__t]) + 1;
}
_LIBCPP_AVAILABILITY_TO_CHARS
static _LIBCPP_HIDE_FROM_ABI char* __convert(_Tp __v, char* __p)
{
return __u32toa(__v, __p);
}
static _LIBCPP_HIDE_FROM_ABI decltype(__pow10_32)& __pow() { return __pow10_32; }
};
template <typename _Tp>
inline _LIBCPP_HIDE_FROM_ABI bool
__mul_overflowed(unsigned char __a, _Tp __b, unsigned char& __r)
{
auto __c = __a * __b;
__r = __c;
return __c > numeric_limits<unsigned char>::max();
}
template <typename _Tp>
inline _LIBCPP_HIDE_FROM_ABI bool
__mul_overflowed(unsigned short __a, _Tp __b, unsigned short& __r)
{
auto __c = __a * __b;
__r = __c;
return __c > numeric_limits<unsigned short>::max();
}
template <typename _Tp>
inline _LIBCPP_HIDE_FROM_ABI bool
__mul_overflowed(_Tp __a, _Tp __b, _Tp& __r)
{
static_assert(is_unsigned<_Tp>::value, "");
#if !defined(_LIBCPP_COMPILER_MSVC)
return __builtin_mul_overflow(__a, __b, &__r);
#else
bool __did = __b && (numeric_limits<_Tp>::max() / __b) < __a;
__r = __a * __b;
return __did;
#endif
}
template <typename _Tp, typename _Up>
inline _LIBCPP_HIDE_FROM_ABI bool
__mul_overflowed(_Tp __a, _Up __b, _Tp& __r)
{
return __mul_overflowed(__a, static_cast<_Tp>(__b), __r);
}
template <typename _Tp>
struct _LIBCPP_HIDDEN __traits : __traits_base<_Tp>
{
static constexpr int digits = numeric_limits<_Tp>::digits10 + 1;
using __traits_base<_Tp>::__pow;
using typename __traits_base<_Tp>::type;
// precondition: at least one non-zero character available
static _LIBCPP_HIDE_FROM_ABI char const*
__read(char const* __p, char const* __ep, type& __a, type& __b)
{
type __cprod[digits];
int __j = digits - 1;
int __i = digits;
do
{
if (!('0' <= *__p && *__p <= '9'))
break;
__cprod[--__i] = *__p++ - '0';
} while (__p != __ep && __i != 0);
__a = __inner_product(__cprod + __i + 1, __cprod + __j, __pow() + 1,
__cprod[__i]);
if (__mul_overflowed(__cprod[__j], __pow()[__j - __i], __b))
--__p;
return __p;
}
template <typename _It1, typename _It2, class _Up>
static _LIBCPP_HIDE_FROM_ABI _Up
__inner_product(_It1 __first1, _It1 __last1, _It2 __first2, _Up __init)
{
for (; __first1 < __last1; ++__first1, ++__first2)
__init = __init + *__first1 * *__first2;
return __init;
}
};
} // namespace __itoa
template <typename _Tp>
inline _LIBCPP_HIDE_FROM_ABI _Tp
__complement(_Tp __x)
{
static_assert(is_unsigned<_Tp>::value, "cast to unsigned first");
return _Tp(~__x + 1);
}
template <typename _Tp>
_LIBCPP_AVAILABILITY_TO_CHARS
inline _LIBCPP_HIDE_FROM_ABI to_chars_result
__to_chars_itoa(char* __first, char* __last, _Tp __value, true_type)
{
auto __x = __to_unsigned_like(__value);
if (__value < 0 && __first != __last)
{
*__first++ = '-';
__x = __complement(__x);
}
return __to_chars_itoa(__first, __last, __x, false_type());
}
template <typename _Tp>
_LIBCPP_AVAILABILITY_TO_CHARS
inline _LIBCPP_HIDE_FROM_ABI to_chars_result
__to_chars_itoa(char* __first, char* __last, _Tp __value, false_type)
{
using __tx = __itoa::__traits<_Tp>;
auto __diff = __last - __first;
if (__tx::digits <= __diff || __tx::__width(__value) <= __diff)
return {__tx::__convert(__value, __first), errc(0)};
else
return {__last, errc::value_too_large};
}
template <typename _Tp>
_LIBCPP_AVAILABILITY_TO_CHARS
inline _LIBCPP_HIDE_FROM_ABI to_chars_result
__to_chars_integral(char* __first, char* __last, _Tp __value, int __base,
true_type)
{
auto __x = __to_unsigned_like(__value);
if (__value < 0 && __first != __last)
{
*__first++ = '-';
__x = __complement(__x);
}
return __to_chars_integral(__first, __last, __x, __base, false_type());
}
template <typename _Tp>
_LIBCPP_AVAILABILITY_TO_CHARS _LIBCPP_HIDE_FROM_ABI int
__to_chars_integral_width(_Tp __value, unsigned __base) {
_LIBCPP_ASSERT(__value >= 0, "The function requires a non-negative value.");
unsigned __base_2 = __base * __base;
unsigned __base_3 = __base_2 * __base;
unsigned __base_4 = __base_2 * __base_2;
int __r = 0;
while (true) {
if (__value < __base)
return __r + 1;
if (__value < __base_2)
return __r + 2;
if (__value < __base_3)
return __r + 3;
if (__value < __base_4)
return __r + 4;
__value /= __base_4;
__r += 4;
}
__libcpp_unreachable();
}
template <typename _Tp>
_LIBCPP_AVAILABILITY_TO_CHARS
inline _LIBCPP_HIDE_FROM_ABI to_chars_result
__to_chars_integral(char* __first, char* __last, _Tp __value, int __base,
false_type)
{
if (__base == 10)
return __to_chars_itoa(__first, __last, __value, false_type());
ptrdiff_t __cap = __last - __first;
int __n = __to_chars_integral_width(__value, __base);
if (__n > __cap)
return {__last, errc::value_too_large};
__last = __first + __n;
char* __p = __last;
do {
unsigned __c = __value % __base;
__value /= __base;
*--__p = "0123456789abcdefghijklmnopqrstuvwxyz"[__c];
} while (__value != 0);
return {__last, errc(0)};
}
template <typename _Tp, typename enable_if<is_integral<_Tp>::value, int>::type = 0>
_LIBCPP_AVAILABILITY_TO_CHARS
inline _LIBCPP_HIDE_FROM_ABI to_chars_result
to_chars(char* __first, char* __last, _Tp __value)
{
return __to_chars_itoa(__first, __last, __value, is_signed<_Tp>());
}
template <typename _Tp, typename enable_if<is_integral<_Tp>::value, int>::type = 0>
_LIBCPP_AVAILABILITY_TO_CHARS
inline _LIBCPP_HIDE_FROM_ABI to_chars_result
to_chars(char* __first, char* __last, _Tp __value, int __base)
{
_LIBCPP_ASSERT(2 <= __base && __base <= 36, "base not in [2, 36]");
return __to_chars_integral(__first, __last, __value, __base,
is_signed<_Tp>());
}
template <typename _It, typename _Tp, typename _Fn, typename... _Ts>
inline _LIBCPP_HIDE_FROM_ABI from_chars_result
__sign_combinator(_It __first, _It __last, _Tp& __value, _Fn __f, _Ts... __args)
{
using __tl = numeric_limits<_Tp>;
decltype(__to_unsigned_like(__value)) __x;
bool __neg = (__first != __last && *__first == '-');
auto __r = __f(__neg ? __first + 1 : __first, __last, __x, __args...);
switch (__r.ec)
{
case errc::invalid_argument:
return {__first, __r.ec};
case errc::result_out_of_range:
return __r;
default:
break;
}
if (__neg)
{
if (__x <= __complement(__to_unsigned_like(__tl::min())))
{
__x = __complement(__x);
std::memcpy(&__value, &__x, sizeof(__x));
return __r;
}
}
else
{
if (__x <= __to_unsigned_like(__tl::max()))
{
__value = __x;
return __r;
}
}
return {__r.ptr, errc::result_out_of_range};
}
template <typename _Tp>
inline _LIBCPP_HIDE_FROM_ABI bool
__in_pattern(_Tp __c)
{
return '0' <= __c && __c <= '9';
}
struct _LIBCPP_HIDDEN __in_pattern_result
{
bool __ok;
int __val;
explicit _LIBCPP_HIDE_FROM_ABI operator bool() const { return __ok; }
};
template <typename _Tp>
inline _LIBCPP_HIDE_FROM_ABI __in_pattern_result
__in_pattern(_Tp __c, int __base)
{
if (__base <= 10)
return {'0' <= __c && __c < '0' + __base, __c - '0'};
else if (__in_pattern(__c))
return {true, __c - '0'};
else if ('a' <= __c && __c < 'a' + __base - 10)
return {true, __c - 'a' + 10};
else
return {'A' <= __c && __c < 'A' + __base - 10, __c - 'A' + 10};
}
template <typename _It, typename _Tp, typename _Fn, typename... _Ts>
inline _LIBCPP_HIDE_FROM_ABI from_chars_result
__subject_seq_combinator(_It __first, _It __last, _Tp& __value, _Fn __f,
_Ts... __args)
{
auto __find_non_zero = [](_It __firstit, _It __lastit) {
for (; __firstit != __lastit; ++__firstit)
if (*__firstit != '0')
break;
return __firstit;
};
auto __p = __find_non_zero(__first, __last);
if (__p == __last || !__in_pattern(*__p, __args...))
{
if (__p == __first)
return {__first, errc::invalid_argument};
else
{
__value = 0;
return {__p, {}};
}
}
auto __r = __f(__p, __last, __value, __args...);
if (__r.ec == errc::result_out_of_range)
{
for (; __r.ptr != __last; ++__r.ptr)
{
if (!__in_pattern(*__r.ptr, __args...))
break;
}
}
return __r;
}
template <typename _Tp, typename enable_if<is_unsigned<_Tp>::value, int>::type = 0>
inline _LIBCPP_HIDE_FROM_ABI from_chars_result
__from_chars_atoi(const char* __first, const char* __last, _Tp& __value)
{
using __tx = __itoa::__traits<_Tp>;
using __output_type = typename __tx::type;
return __subject_seq_combinator(
__first, __last, __value,
[](const char* _First, const char* _Last,
_Tp& __val) -> from_chars_result {
__output_type __a, __b;
auto __p = __tx::__read(_First, _Last, __a, __b);
if (__p == _Last || !__in_pattern(*__p))
{
__output_type __m = numeric_limits<_Tp>::max();
if (__m >= __a && __m - __a >= __b)
{
__val = __a + __b;
return {__p, {}};
}
}
return {__p, errc::result_out_of_range};
});
}
template <typename _Tp, typename enable_if<is_signed<_Tp>::value, int>::type = 0>
inline _LIBCPP_HIDE_FROM_ABI from_chars_result
__from_chars_atoi(const char* __first, const char* __last, _Tp& __value)
{
using __t = decltype(__to_unsigned_like(__value));
return __sign_combinator(__first, __last, __value, __from_chars_atoi<__t>);
}
template <typename _Tp, typename enable_if<is_unsigned<_Tp>::value, int>::type = 0>
inline _LIBCPP_HIDE_FROM_ABI from_chars_result
__from_chars_integral(const char* __first, const char* __last, _Tp& __value,
int __base)
{
if (__base == 10)
return __from_chars_atoi(__first, __last, __value);
return __subject_seq_combinator(
__first, __last, __value,
[](const char* __p, const char* __lastp, _Tp& __val,
int _Base) -> from_chars_result {
using __tl = numeric_limits<_Tp>;
auto __digits = __tl::digits / log2f(float(_Base));
_Tp __a = __in_pattern(*__p++, _Base).__val, __b = 0;
for (int __i = 1; __p != __lastp; ++__i, ++__p)
{
if (auto __c = __in_pattern(*__p, _Base))
{
if (__i < __digits - 1)
__a = __a * _Base + __c.__val;
else
{
if (!__itoa::__mul_overflowed(__a, _Base, __a))
++__p;
__b = __c.__val;
break;
}
}
else
break;
}
if (__p == __lastp || !__in_pattern(*__p, _Base))
{
if (__tl::max() - __a >= __b)
{
__val = __a + __b;
return {__p, {}};
}
}
return {__p, errc::result_out_of_range};
},
__base);
}
template <typename _Tp, typename enable_if<is_signed<_Tp>::value, int>::type = 0>
inline _LIBCPP_HIDE_FROM_ABI from_chars_result
__from_chars_integral(const char* __first, const char* __last, _Tp& __value,
int __base)
{
using __t = decltype(__to_unsigned_like(__value));
return __sign_combinator(__first, __last, __value,
__from_chars_integral<__t>, __base);
}
template <typename _Tp, typename enable_if<is_integral<_Tp>::value, int>::type = 0>
inline _LIBCPP_HIDE_FROM_ABI from_chars_result
from_chars(const char* __first, const char* __last, _Tp& __value)
{
return __from_chars_atoi(__first, __last, __value);
}
template <typename _Tp, typename enable_if<is_integral<_Tp>::value, int>::type = 0>
inline _LIBCPP_HIDE_FROM_ABI from_chars_result
from_chars(const char* __first, const char* __last, _Tp& __value, int __base)
{
_LIBCPP_ASSERT(2 <= __base && __base <= 36, "base not in [2, 36]");
return __from_chars_integral(__first, __last, __value, __base);
}
// Floating-point implementation starts here.
// Unlike the other parts of charconv this is only available in C++17 and newer.
#if _LIBCPP_STD_VER > 14
_LIBCPP_AVAILABILITY_TO_CHARS_FLOATING_POINT _LIBCPP_FUNC_VIS
to_chars_result to_chars(char* __first, char* __last, float __value);
_LIBCPP_AVAILABILITY_TO_CHARS_FLOATING_POINT _LIBCPP_FUNC_VIS
to_chars_result to_chars(char* __first, char* __last, double __value);
_LIBCPP_AVAILABILITY_TO_CHARS_FLOATING_POINT _LIBCPP_FUNC_VIS
to_chars_result to_chars(char* __first, char* __last, long double __value);
_LIBCPP_AVAILABILITY_TO_CHARS_FLOATING_POINT _LIBCPP_FUNC_VIS
to_chars_result to_chars(char* __first, char* __last, float __value, chars_format __fmt);
_LIBCPP_AVAILABILITY_TO_CHARS_FLOATING_POINT _LIBCPP_FUNC_VIS
to_chars_result to_chars(char* __first, char* __last, double __value, chars_format __fmt);
_LIBCPP_AVAILABILITY_TO_CHARS_FLOATING_POINT _LIBCPP_FUNC_VIS
to_chars_result to_chars(char* __first, char* __last, long double __value, chars_format __fmt);
_LIBCPP_AVAILABILITY_TO_CHARS_FLOATING_POINT _LIBCPP_FUNC_VIS
to_chars_result to_chars(char* __first, char* __last, float __value, chars_format __fmt, int __precision);
_LIBCPP_AVAILABILITY_TO_CHARS_FLOATING_POINT _LIBCPP_FUNC_VIS
to_chars_result to_chars(char* __first, char* __last, double __value, chars_format __fmt, int __precision);
_LIBCPP_AVAILABILITY_TO_CHARS_FLOATING_POINT _LIBCPP_FUNC_VIS
to_chars_result to_chars(char* __first, char* __last, long double __value, chars_format __fmt, int __precision);
# endif // _LIBCPP_STD_VER > 14
#endif // _LIBCPP_CXX03_LANG
_LIBCPP_END_NAMESPACE_STD
_LIBCPP_POP_MACROS
#endif // _LIBCPP_CHARCONV
Reference in New Issue View Git Blame Copy Permalink