[libcxx-commits] [libcxx] [libc++] Optimize num_get integral functions (PR #121795)
Nikolas Klauser via libcxx-commits
libcxx-commits at lists.llvm.org
Thu Jan 30 12:06:28 PST 2025
https://github.com/philnik777 updated https://github.com/llvm/llvm-project/pull/121795
>From ae3fb04abb00481a1a28684a60074822ba769465 Mon Sep 17 00:00:00 2001
From: Nikolas Klauser <nikolasklauser at berlin.de>
Date: Sun, 5 Jan 2025 13:14:32 +0100
Subject: [PATCH] [libc++] Optimize num_get integral functions
---
libcxx/docs/ReleaseNotes/20.rst | 2 +
libcxx/include/__algorithm/simd_utils.h | 25 ++
libcxx/include/__locale_dir/locale_base_api.h | 11 -
.../include/__locale_dir/support/bsd_like.h | 9 -
libcxx/include/__locale_dir/support/windows.h | 8 -
libcxx/include/locale | 305 +++++++++---------
.../facet.num.get.members/get_long.pass.cpp | 12 +
7 files changed, 191 insertions(+), 181 deletions(-)
diff --git a/libcxx/docs/ReleaseNotes/20.rst b/libcxx/docs/ReleaseNotes/20.rst
index 57ab0c167544bc3..d8e275020f6f45f 100644
--- a/libcxx/docs/ReleaseNotes/20.rst
+++ b/libcxx/docs/ReleaseNotes/20.rst
@@ -120,6 +120,8 @@ Improvements and New Features
- Added :ref:`hardening mode <hardening>` support for ``forward_list`` and ``bitset``.
+- The ``num_get::do_get`` integral overloads have been optimized. resulting in a performance improvement of up to 2.8x.
+
Deprecations and Removals
-------------------------
diff --git a/libcxx/include/__algorithm/simd_utils.h b/libcxx/include/__algorithm/simd_utils.h
index 4e03723a3285436..987cf09cf48f7f8 100644
--- a/libcxx/include/__algorithm/simd_utils.h
+++ b/libcxx/include/__algorithm/simd_utils.h
@@ -116,11 +116,36 @@ template <class _VecT, class _Iter>
}(make_index_sequence<__simd_vector_size_v<_VecT>>{});
}
+// Load the first _Np elements, zero the rest
+_LIBCPP_DIAGNOSTIC_PUSH
+_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wpsabi")
+template <class _VecT, size_t _Np, class _Iter>
+[[__nodiscard__]] _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _VecT __partial_load(_Iter __iter) noexcept {
+ return [=]<size_t... _LoadIndices, size_t... _ZeroIndices>(
+ index_sequence<_LoadIndices...>, index_sequence<_ZeroIndices...>) _LIBCPP_ALWAYS_INLINE noexcept {
+ return _VecT{__iter[_LoadIndices]...};
+ }(make_index_sequence<_Np>{}, make_index_sequence<__simd_vector_size_v<_VecT> - _Np>{});
+}
+
+template <class _VecT>
+[[__nodiscard__]] _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _VecT
+__broadcast(__simd_vector_underlying_type_t<_VecT> __val) {
+ return [&]<std::size_t... _Indices>(index_sequence<_Indices...>) {
+ return _VecT{((void)_Indices, __val)...};
+ }(make_index_sequence<__simd_vector_size_v<_VecT>>());
+}
+_LIBCPP_DIAGNOSTIC_POP
+
template <class _Tp, size_t _Np>
[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI bool __all_of(__simd_vector<_Tp, _Np> __vec) noexcept {
return __builtin_reduce_and(__builtin_convertvector(__vec, __simd_vector<bool, _Np>));
}
+template <class _Tp, size_t _Np>
+[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI bool __none_of(__simd_vector<_Tp, _Np> __vec) noexcept {
+ return !__builtin_reduce_or(__vec);
+}
+
template <class _Tp, size_t _Np>
[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI size_t __find_first_set(__simd_vector<_Tp, _Np> __vec) noexcept {
using __mask_vec = __simd_vector<bool, _Np>;
diff --git a/libcxx/include/__locale_dir/locale_base_api.h b/libcxx/include/__locale_dir/locale_base_api.h
index bbee9f49867fd9c..efe1e9fae44acdf 100644
--- a/libcxx/include/__locale_dir/locale_base_api.h
+++ b/libcxx/include/__locale_dir/locale_base_api.h
@@ -51,8 +51,6 @@
// float __strtof(const char*, char**, __locale_t);
// double __strtod(const char*, char**, __locale_t);
// long double __strtold(const char*, char**, __locale_t);
-// long long __strtoll(const char*, char**, __locale_t);
-// unsigned long long __strtoull(const char*, char**, __locale_t);
// }
//
// Character manipulation functions
@@ -182,15 +180,6 @@ inline _LIBCPP_HIDE_FROM_ABI long double __strtold(const char* __nptr, char** __
return strtold_l(__nptr, __endptr, __loc);
}
-inline _LIBCPP_HIDE_FROM_ABI long long __strtoll(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
- return strtoll_l(__nptr, __endptr, __base, __loc);
-}
-
-inline _LIBCPP_HIDE_FROM_ABI unsigned long long
-__strtoull(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
- return strtoull_l(__nptr, __endptr, __base, __loc);
-}
-
//
// Character manipulation functions
//
diff --git a/libcxx/include/__locale_dir/support/bsd_like.h b/libcxx/include/__locale_dir/support/bsd_like.h
index c0080b13a08cf36..6ebf7726f0fab65 100644
--- a/libcxx/include/__locale_dir/support/bsd_like.h
+++ b/libcxx/include/__locale_dir/support/bsd_like.h
@@ -75,15 +75,6 @@ inline _LIBCPP_HIDE_FROM_ABI long double __strtold(const char* __nptr, char** __
return ::strtold_l(__nptr, __endptr, __loc);
}
-inline _LIBCPP_HIDE_FROM_ABI long long __strtoll(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
- return ::strtoll_l(__nptr, __endptr, __base, __loc);
-}
-
-inline _LIBCPP_HIDE_FROM_ABI unsigned long long
-__strtoull(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
- return ::strtoull_l(__nptr, __endptr, __base, __loc);
-}
-
//
// Character manipulation functions
//
diff --git a/libcxx/include/__locale_dir/support/windows.h b/libcxx/include/__locale_dir/support/windows.h
index ff89d3e87eb44e5..c3b24ca01318162 100644
--- a/libcxx/include/__locale_dir/support/windows.h
+++ b/libcxx/include/__locale_dir/support/windows.h
@@ -184,14 +184,6 @@ inline _LIBCPP_HIDE_FROM_ABI double __strtod(const char* __nptr, char** __endptr
return ::_strtod_l(__nptr, __endptr, __loc);
}
-inline _LIBCPP_HIDE_FROM_ABI long long __strtoll(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
- return ::_strtoi64_l(__nptr, __endptr, __base, __loc);
-}
-inline _LIBCPP_HIDE_FROM_ABI unsigned long long
-__strtoull(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
- return ::_strtoui64_l(__nptr, __endptr, __base, __loc);
-}
-
//
// Character manipulation functions
//
diff --git a/libcxx/include/locale b/libcxx/include/locale
index be0f31cece671fb..cd06dba8adbe60e 100644
--- a/libcxx/include/locale
+++ b/libcxx/include/locale
@@ -198,7 +198,9 @@ template <class charT> class messages_byname;
# include <__algorithm/equal.h>
# include <__algorithm/find.h>
# include <__algorithm/max.h>
+# include <__algorithm/min.h>
# include <__algorithm/reverse.h>
+# include <__algorithm/simd_utils.h>
# include <__algorithm/unwrap_iter.h>
# include <__assert>
# include <__iterator/access.h>
@@ -375,7 +377,7 @@ struct _LIBCPP_EXPORTED_FROM_ABI __num_get_base {
static int __get_base(ios_base&);
static const char __src[33]; // "0123456789abcdefABCDEFxX+-pPiInN"
// count of leading characters in __src used for parsing integers ("012..X+-")
- static const size_t __int_chr_cnt = 26;
+ static inline const size_t __int_chr_cnt = 26;
// count of leading characters in __src used for parsing floating-point values ("012..-pP")
static const size_t __fp_chr_cnt = 28;
};
@@ -403,6 +405,27 @@ struct __num_get : protected __num_get_base {
[[__deprecated__("This exists only for ABI compatibility")]] static string
__stage2_int_prep(ios_base& __iob, _CharT* __atoms, _CharT& __thousands_sep);
+
+ _LIBCPP_HIDE_FROM_ABI static ptrdiff_t __atoms_offset(const _CharT* __atoms, _CharT __val) {
+# if _LIBCPP_HAS_ALGORITHM_VECTOR_UTILS
+ _LIBCPP_DIAGNOSTIC_PUSH
+ _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wpsabi")
+ if constexpr (is_same<_CharT, char>::value) {
+ using __vec = __simd_vector<char, 32>;
+ __vec __chars = std::__broadcast<__vec>(__val);
+ __vec __cmp = std::__partial_load<__vec, __int_chr_cnt>(__atoms);
+ auto __res = __chars == __cmp;
+ if (std::__none_of(__res))
+ return __int_chr_cnt;
+ return std::min(__int_chr_cnt, std::__find_first_set(__res));
+ } else
+ _LIBCPP_DIAGNOSTIC_POP
+# endif
+ {
+ return std::find(__atoms, __atoms + __int_chr_cnt, __val) - __atoms;
+ }
+ }
+
static int __stage2_int_loop(
_CharT __ct,
int __base,
@@ -476,7 +499,7 @@ int __num_get<_CharT>::__stage2_int_loop(
}
return 0;
}
- ptrdiff_t __f = std::find(__atoms, __atoms + __int_chr_cnt, __ct) - __atoms;
+ ptrdiff_t __f = __atoms_offset(__atoms, __ct);
if (__f >= 24)
return -1;
switch (__base) {
@@ -637,43 +660,39 @@ protected:
_LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS iter_type
__do_get_floating_point(iter_type __b, iter_type __e, ios_base& __iob, ios_base::iostate& __err, _Fp& __v) const;
- template <class _Signed>
- _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS iter_type
- __do_get_signed(iter_type __b, iter_type __e, ios_base& __iob, ios_base::iostate& __err, _Signed& __v) const;
-
- template <class _Unsigned>
+ template <class _MaybeSigned>
_LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS iter_type
- __do_get_unsigned(iter_type __b, iter_type __e, ios_base& __iob, ios_base::iostate& __err, _Unsigned& __v) const;
+ __do_get_integral(iter_type __b, iter_type __e, ios_base& __iob, ios_base::iostate& __err, _MaybeSigned& __v) const;
virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob, ios_base::iostate& __err, bool& __v) const;
virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob, ios_base::iostate& __err, long& __v) const {
- return this->__do_get_signed(__b, __e, __iob, __err, __v);
+ return this->__do_get_integral(__b, __e, __iob, __err, __v);
}
virtual iter_type
do_get(iter_type __b, iter_type __e, ios_base& __iob, ios_base::iostate& __err, long long& __v) const {
- return this->__do_get_signed(__b, __e, __iob, __err, __v);
+ return this->__do_get_integral(__b, __e, __iob, __err, __v);
}
virtual iter_type
do_get(iter_type __b, iter_type __e, ios_base& __iob, ios_base::iostate& __err, unsigned short& __v) const {
- return this->__do_get_unsigned(__b, __e, __iob, __err, __v);
+ return this->__do_get_integral(__b, __e, __iob, __err, __v);
}
virtual iter_type
do_get(iter_type __b, iter_type __e, ios_base& __iob, ios_base::iostate& __err, unsigned int& __v) const {
- return this->__do_get_unsigned(__b, __e, __iob, __err, __v);
+ return this->__do_get_integral(__b, __e, __iob, __err, __v);
}
virtual iter_type
do_get(iter_type __b, iter_type __e, ios_base& __iob, ios_base::iostate& __err, unsigned long& __v) const {
- return this->__do_get_unsigned(__b, __e, __iob, __err, __v);
+ return this->__do_get_integral(__b, __e, __iob, __err, __v);
}
virtual iter_type
do_get(iter_type __b, iter_type __e, ios_base& __iob, ios_base::iostate& __err, unsigned long long& __v) const {
- return this->__do_get_unsigned(__b, __e, __iob, __err, __v);
+ return this->__do_get_integral(__b, __e, __iob, __err, __v);
}
virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob, ios_base::iostate& __err, float& __v) const {
@@ -695,65 +714,6 @@ protected:
template <class _CharT, class _InputIterator>
locale::id num_get<_CharT, _InputIterator>::id;
-template <class _Tp>
-_LIBCPP_HIDE_FROM_ABI _Tp
-__num_get_signed_integral(const char* __a, const char* __a_end, ios_base::iostate& __err, int __base) {
- if (__a != __a_end) {
- __libcpp_remove_reference_t<decltype(errno)> __save_errno = errno;
- errno = 0;
- char* __p2;
- long long __ll = __locale::__strtoll(__a, &__p2, __base, _LIBCPP_GET_C_LOCALE);
- __libcpp_remove_reference_t<decltype(errno)> __current_errno = errno;
- if (__current_errno == 0)
- errno = __save_errno;
- if (__p2 != __a_end) {
- __err = ios_base::failbit;
- return 0;
- } else if (__current_errno == ERANGE || __ll < numeric_limits<_Tp>::min() || numeric_limits<_Tp>::max() < __ll) {
- __err = ios_base::failbit;
- if (__ll > 0)
- return numeric_limits<_Tp>::max();
- else
- return numeric_limits<_Tp>::min();
- }
- return static_cast<_Tp>(__ll);
- }
- __err = ios_base::failbit;
- return 0;
-}
-
-template <class _Tp>
-_LIBCPP_HIDE_FROM_ABI _Tp
-__num_get_unsigned_integral(const char* __a, const char* __a_end, ios_base::iostate& __err, int __base) {
- if (__a != __a_end) {
- const bool __negate = *__a == '-';
- if (__negate && ++__a == __a_end) {
- __err = ios_base::failbit;
- return 0;
- }
- __libcpp_remove_reference_t<decltype(errno)> __save_errno = errno;
- errno = 0;
- char* __p2;
- unsigned long long __ll = __locale::__strtoull(__a, &__p2, __base, _LIBCPP_GET_C_LOCALE);
- __libcpp_remove_reference_t<decltype(errno)> __current_errno = errno;
- if (__current_errno == 0)
- errno = __save_errno;
- if (__p2 != __a_end) {
- __err = ios_base::failbit;
- return 0;
- } else if (__current_errno == ERANGE || numeric_limits<_Tp>::max() < __ll) {
- __err = ios_base::failbit;
- return numeric_limits<_Tp>::max();
- }
- _Tp __res = static_cast<_Tp>(__ll);
- if (__negate)
- __res = -__res;
- return __res;
- }
- __err = ios_base::failbit;
- return 0;
-}
-
template <class _Tp>
_LIBCPP_HIDE_FROM_ABI _Tp __do_strtod(const char* __a, char** __p2);
@@ -822,12 +782,12 @@ _InputIterator num_get<_CharT, _InputIterator>::do_get(
return __b;
}
-// signed
-
template <class _CharT, class _InputIterator>
-template <class _Signed>
-_InputIterator num_get<_CharT, _InputIterator>::__do_get_signed(
- iter_type __b, iter_type __e, ios_base& __iob, ios_base::iostate& __err, _Signed& __v) const {
+template <class _MaybeSigned>
+_InputIterator num_get<_CharT, _InputIterator>::__do_get_integral(
+ iter_type __first, iter_type __last, ios_base& __iob, ios_base::iostate& __err, _MaybeSigned& __v) const {
+ using _Unsigned = __make_unsigned_t<_MaybeSigned>;
+
// Stage 1
int __base = this->__get_base(__iob);
// Stage 2
@@ -836,98 +796,137 @@ _InputIterator num_get<_CharT, _InputIterator>::__do_get_signed(
char_type __atoms1[__atoms_size];
const char_type* __atoms = this->__do_widen(__iob, __atoms1);
string __grouping = this->__stage2_int_prep(__iob, __thousands_sep);
- string __buf;
- __buf.resize(__buf.capacity());
- char* __a = &__buf[0];
- char* __a_end = __a;
unsigned __g[__num_get_base::__num_get_buf_sz];
unsigned* __g_end = __g;
unsigned __dc = 0;
- for (; __b != __e; ++__b) {
- if (__a_end == __a + __buf.size()) {
- size_t __tmp = __buf.size();
- __buf.resize(2 * __buf.size());
- __buf.resize(__buf.capacity());
- __a = &__buf[0];
- __a_end = __a + __tmp;
+
+ if (__first == __last) {
+ __err |= ios_base::eofbit;
+ return __first;
+ }
+
+ while (!__grouping.empty() && *__first == __thousands_sep) {
+ ++__first;
+ if (__g_end - __g < this->__num_get_buf_sz) {
+ *__g_end++ = __dc;
+ __dc = 0;
}
- if (this->__stage2_int_loop(
- *__b,
- __base,
- __a,
- __a_end,
- __dc,
- __thousands_sep,
- __grouping,
- __g,
- __g_end,
- const_cast<char_type*>(__atoms)))
- break;
}
- if (__grouping.size() != 0 && __g_end - __g < __num_get_base::__num_get_buf_sz)
- *__g_end++ = __dc;
- // Stage 3
- __v = std::__num_get_signed_integral<_Signed>(__a, __a_end, __err, __base);
- // Digit grouping checked
- __check_grouping(__grouping, __g, __g_end, __err);
- // EOF checked
- if (__b == __e)
+
+ bool __negate = false;
+ // __c == '+' || __c == '-'
+ if (auto __c = *__first; __c == __atoms[24] || __c == __atoms[25]) {
+ __negate = __c == __atoms[25];
+ ++__first;
+ }
+
+ if (__first == __last) {
__err |= ios_base::eofbit;
- return __b;
-}
+ return __first;
+ }
-// unsigned
+ bool __parsed_num = false;
-template <class _CharT, class _InputIterator>
-template <class _Unsigned>
-_InputIterator num_get<_CharT, _InputIterator>::__do_get_unsigned(
- iter_type __b, iter_type __e, ios_base& __iob, ios_base::iostate& __err, _Unsigned& __v) const {
- // Stage 1
- int __base = this->__get_base(__iob);
- // Stage 2
- char_type __thousands_sep;
- const int __atoms_size = __num_get_base::__int_chr_cnt;
- char_type __atoms1[__atoms_size];
- const char_type* __atoms = this->__do_widen(__iob, __atoms1);
- string __grouping = this->__stage2_int_prep(__iob, __thousands_sep);
- string __buf;
- __buf.resize(__buf.capacity());
- char* __a = &__buf[0];
- char* __a_end = __a;
- unsigned __g[__num_get_base::__num_get_buf_sz];
- unsigned* __g_end = __g;
- unsigned __dc = 0;
- for (; __b != __e; ++__b) {
- if (__a_end == __a + __buf.size()) {
- size_t __tmp = __buf.size();
- __buf.resize(2 * __buf.size());
- __buf.resize(__buf.capacity());
- __a = &__buf[0];
- __a_end = __a + __tmp;
+ // If we don't have a pre-set base, figure it out
+ if (__base == 0) {
+ auto __c = *__first;
+ // __c == '0'
+ if (__c == __atoms[0]) {
+ ++__first;
+ if (__first == __last) {
+ __err |= ios_base::eofbit;
+ return __first;
+ }
+ // __c2 == 'x' || __c2 == 'X'
+ if (auto __c2 = *__first; __c2 == __atoms[22] || __c2 == __atoms[23]) {
+ __base = 16;
+ ++__first;
+ } else {
+ __base = 8;
+ }
+ } else {
+ __base = 10;
}
- if (this->__stage2_int_loop(
- *__b,
- __base,
- __a,
- __a_end,
- __dc,
- __thousands_sep,
- __grouping,
- __g,
- __g_end,
- const_cast<char_type*>(__atoms)))
+ } else if (__base == 16) {
+ // Try to swallow '0x'
+
+ // *__first == '0'
+ if (*__first == __atoms[0]) {
+ ++__first;
+ if (__first == __last) {
+ __err |= ios_base::eofbit;
+ return __first;
+ }
+ // __c == 'x' || __c == 'X'
+ if (auto __c = *__first; __c == __atoms[22] || __c == __atoms[23])
+ ++__first;
+ else
+ __parsed_num = true; // We only swallowed '0', so we've started to parse a number
+ }
+ }
+
+ // Calculate the actual number
+ _Unsigned __val = 0;
+ bool __overflowed = false;
+ for (; __first != __last; ++__first) {
+ auto __c = *__first;
+ if (!__grouping.empty() && __c == __thousands_sep) {
+ if (__g_end - __g < this->__num_get_buf_sz) {
+ *__g_end++ = __dc;
+ __dc = 0;
+ }
+ continue;
+ }
+ auto __offset = this->__atoms_offset(__atoms, __c);
+ if (__offset >= 22)
break;
+
+ if (__base == 16 && __offset >= 16)
+ __offset -= 6;
+ if (__offset >= __base)
+ break;
+ __overflowed |= __builtin_mul_overflow(__val, __base, &__val) || __builtin_add_overflow(__val, __offset, &__val);
+ __parsed_num = true;
+ ++__dc;
+ }
+
+ if (!__parsed_num) {
+ __err |= ios_base::failbit;
+ __v = 0;
+ } else if (__overflowed) {
+ __err |= ios_base::failbit;
+ __v = is_signed<_MaybeSigned>::value && __negate
+ ? numeric_limits<_MaybeSigned>::min()
+ : numeric_limits<_MaybeSigned>::max();
+ } else if (!__negate) {
+ if (__val > static_cast<_Unsigned>(numeric_limits<_MaybeSigned>::max())) {
+ __err |= ios_base::failbit;
+ __v = numeric_limits<_MaybeSigned>::max();
+ } else {
+ __v = __val;
+ }
+ } else if (is_signed<_MaybeSigned>::value) {
+ if (__val > static_cast<_Unsigned>(numeric_limits<_MaybeSigned>::max()) + 1) {
+ __err |= ios_base::failbit;
+ __v = numeric_limits<_MaybeSigned>::min();
+ } else if (__val == static_cast<_Unsigned>(numeric_limits<_MaybeSigned>::max()) + 1) {
+ __v = numeric_limits<_MaybeSigned>::min();
+ } else {
+ __v = -__val;
+ }
+ } else {
+ __v = -__val;
}
+
if (__grouping.size() != 0 && __g_end - __g < __num_get_base::__num_get_buf_sz)
*__g_end++ = __dc;
- // Stage 3
- __v = std::__num_get_unsigned_integral<_Unsigned>(__a, __a_end, __err, __base);
+
// Digit grouping checked
__check_grouping(__grouping, __g, __g_end, __err);
// EOF checked
- if (__b == __e)
+ if (__first == __last)
__err |= ios_base::eofbit;
- return __b;
+ return __first;
}
// floating point
diff --git a/libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_long.pass.cpp b/libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_long.pass.cpp
index 03b74ebf5393677..6bf38bd8c72a1ac 100644
--- a/libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_long.pass.cpp
+++ b/libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_long.pass.cpp
@@ -102,6 +102,18 @@ int main(int, char**)
assert(err == ios.goodbit);
assert(v == 291);
}
+ {
+ const char str[] = "a123";
+ std::dec(ios);
+ std::ios_base::iostate err = ios.goodbit;
+ cpp17_input_iterator<const char*> iter =
+ f.get(cpp17_input_iterator<const char*>(str),
+ cpp17_input_iterator<const char*>(str+sizeof(str)),
+ ios, err, v);
+ assert(base(iter) == str);
+ assert(err == ios.failbit);
+ assert(v == 0);
+ }
{
const char str[] = "0x123";
std::hex(ios);
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