PR libstdc++/91748
* include/bits/stl_algo.h (for_each_n): Fix random access iterator
case.
* testsuite/25_algorithms/for_each/for_each_n.cc: Test with random
access iterators.
From-SVN: r275683
The standard requires overloads of std::to_chars for char and (un)signed
integer types. This means that our constrained function template is
non-conforming, because the difference is observable when using types
that convert to an integer (e.g. wchar_t, which promotes).
As well as defining the deleted bool overload for LWG 3266, replace the
constrained function template with overloads for each type.
* include/std/charconv (to_chars): Rename to __to_chars_i. Define
non-template overloads for each signed and unsigned integer type and
char. Define deleted overload for bool (LWG 3266).
* testsuite/20_util/to_chars/1_neg.cc: Remove.
* testsuite/20_util/to_chars/3.cc: New test.
* testsuite/20_util/to_chars/lwg3266.cc: New test.
From-SVN: r275588
Define partial specializations for std::remove_cv so that
std::remove_const and std::remove_volatile don't need to be
instantiated.
* include/std/type_traits (__remove_cv_t): New alias template.
(is_void, is_integral, is_floating_point, is_pointer)
(is_member_object_pointer, is_member_function_pointer, is_null_pointer)
(is_member_point), __is_signed_integer, __is_unsigned_integer)
(__make_unsigned_selector, __make_signed_selector, remove_pointer)
(__decay_selector): Use __remove_cv_t.
(remove_cv): Add partial specializations for cv-qualified types.
(__decay_t): New alias template.
(__decay_and_strip, __common_type_impl, __result_of_impl): Use
__decay_t.
(__enable_if_t): Move earlier in the file.
(_Require): Use __enable_if_t.
(swap(T&, T&)): Use _Require.
(swap(T(&)[N])): Use __enable_if_t.
From-SVN: r275562
__to_chars_10_impl is quite fast. According to the IACA the main loop
takes only 6.0 cycles, the whole function with one iteration takes
10.0 cycles. Replacing the __first[pos] and __first[pos - 1] with
__first[0] and __first[1] drops the function time to 7.53 cycles.
2019-09-09 Antony Polukhin <antoshkka@gmail.com>
* include/bits/charconv.h (__detail::__to_chars_10_impl): Replace
final offsets with constants.
From-SVN: r275514
This patch simplifies the constraints on the constructors from arrays by
removing the redundant checks that element_type and value_type are
convertible to element_type. The incorrect uses of __adl_data in those
constructors are removed as well (they should use std::data not
std::ranges::data, and the former doesn't use ADL).
The range/container constructors are now constrained to exclude all
specializations of std::span, not just the current instantiation. The
range constructor now also checks s subset of the contiguous_range
requirements.
All relevant constructor constraints now use the _Require helper in
order to short circuit and avoid unnecessary instantiations after the
first failed constraint.
A new constructor supports initialization from different specializations
of std::span<OtherType, OtherExtent>, as specified in the C++20 draft.
* include/bits/range_access.h (__adl_to_address): Remove.
* include/std/span (__is_base_derived_safe_convertible_v): Replace
with span::__is_compatible.
(__is_std_array_v): Replace with __is_std_array class template and
partial specializations.
(__is_std_array, __is_std_span): New class templates and partial
specializations.
(span::__is_compatible): New alias template for SFINAE constraints.
(span::span(element_type (&)[N])): Remove redundant constraints. Do
not use __adl_data to obtain a pointer.
(span::span(array<value_type, N>&)): Likewise.
(span::span(const array<value_type, N>&)): Likewise.
[_GLIBCXX_P1394] (span::iter_reference_t, span::iterator_t)
(span::iter_value_t, span::derived_from): New alias templates for
SFINAE constraints, until the equivalents are supported in <concepts>
and <iterator>.
[_GLIBCXX_P1394] (span::__is_compatible_iterator): New alias template
for SFINAE constraints.
[_GLIBCXX_P1394] (span::is_compatible_range): New class template for
SFINAE constraints.
[_GLIBCXX_P1394] (span::span(Range&&)): Improve constraints.
[_GLIBCXX_P1394] (span::span(ContiguousIterator, Sentinel)): Likewise.
Use std::to_address instead of __adl_to_address.
[_GLIBCXX_P1394] (span::span(ContiguousIterator, size_type)): Likewise.
[!_GLIBCXX_P1394] (span::__is_compatible_container): New alias
template for SFINAE constraints.
[!_GLIBCXX_P1394] (span::span(Container&))
(span::span(const Container&)): Improve constraints.
[!_GLIBCXX_P1394] (span::span(pointer, size_type))
(span::span(pointer, pointer)): Remove redundant cast of pointer.
(span(const span<OType, OExtent>&)): New constructor.
From-SVN: r275513
The pthread_cond_clockwait function is available in glibc since the 2.30
release. If this function is available in the C library it can be used
to fix PR libstdc++/41861 by supporting std::chrono::steady_clock
properly with std::condition_variable.
This means that code using std::condition_variable::wait_for or
std::condition_variable::wait_until with std::chrono::steady_clock is no
longer subject to timing out early or potentially waiting for much
longer if the system clock is warped at an inopportune moment.
If pthread_cond_clockwait is available then std::chrono::steady_clock is
deemed to be the "best" clock available which means that it is used for
the relative wait_for calls and absolute wait_until calls using
user-defined clocks. Calls explicitly using std::chrono::system_clock
continue to use CLOCK_REALTIME via __gthread_cond_timedwait.
If pthread_cond_clockwait is not available then
std::chrono::system_clock is deemed to be the "best" clock available
which means that the previous suboptimal behaviour remains.
2019-09-04 Mike Crowe <mac@mcrowe.com>
PR libstdc++/41861
* acinclude.m4 (GLIBCXX_CHECK_PTHREAD_COND_CLOCKWAIT): Check for new
pthread_cond_clockwait function.
* configure.ac: Use GLIBCXX_CHECK_PTHREAD_COND_CLOCKWAIT.
* configure: Regenerate.
* config.h.in: Regenerate.
* include/std/condition_variable: (condition_variable): Rename
__steady_clock_t typedef and add system_clock. Change __clock_t to be
a typedef for the preferred clock to convert arbitrary other clocks to.
[_GLIBCXX_USE_PTHREAD_COND_CLOCKWAIT] (wait_until): Add a steady_clock
overload.
(wait_until): Change __clock_t overload to use system_clock.
[_GLIBCXX_USE_PTHREAD_COND_CLOCKWAIT] (__wait_until_impl): Add
steady_clock overload that calls pthread_cond_clockwait.
(__wait_until_impl): Change __clock_t overload to use system_clock.
(condition_variable_any) [_GLIBCXX_USE_PTHREAD_COND_CLOCKWAIT]: Use
steady_clock for __clock_t if pthread_cond_clockwait is available.
From-SVN: r275390
Bunch of micro optimizations for std::to_chars:
* For base == 8 replacing the lookup in __digits table with arithmetic
computations leads to a same CPU cycles for a loop (exchanges two movzx
with 3 bit ops). However this saves 129 bytes of data and totally avoids
a chance of cache misses on __digits.
* For base == 16 replacing the lookup in __digits table with
arithmetic computations leads to a few additional instructions, but
totally avoids a chance of cache misses on __digits (- ~9 cache misses
for worst case) and saves 513 bytes of const data.
* Replacing __first[pos] and __first[pos - 1] with __first[1] and
__first[0] on final iterations saves ~2% of code size.
* Removing trailing '\0' from arrays of digits allows the linker to
merge the symbols (so that "0123456789abcdefghijklmnopqrstuvwxyz" and
"0123456789abcdef" could share the same address). This improves data
locality and reduces binary sizes.
* Using __detail::__to_chars_len_2 instead of a generic
__detail::__to_chars_len makes the operation O(1) instead of O(N). It
also makes the code two times shorter.
In sum: this significantly reduces the size of a binary (for about 4KBs
only for base-8 conversion), deals with latency (CPU cache misses)
without changing the iterations count and without adding costly
instructions into the loops.
2019-08-30 Antony Polukhin <antoshkka@gmail.com>
* include/std/charconv (__detail::__to_chars_8)
__detail::__to_chars_16): Replace array of precomputed digits with
arithmetic operations to avoid CPU cache misses. Remove zero
termination from array of digits to allow symbol merge with generic
implementation of __detail::__to_chars. Replace final offsets with
constants. Use __detail::__to_chars_len_2 instead of a generic
__detail::__to_chars_len.
(__detail::__to_chars): Remove zero termination from array of digits.
(__detail::__to_chars_2): Leading digit is always '1'.
From-SVN: r275205
The memmove optimizations for std::uninitialized_copy/fill/_n will
compile even if the type is not copy constructible, because std::copy
doesn't require copy construction to work. But the uninitialized
algorithms do require it.
This adds explicit static assertions to ensure we don't allow ill-formed
initializations.
PR libstdc++/89164
* include/bits/stl_algobase.h (__copy_move): Give descriptive names
to template parameters.
* include/bits/stl_uninitialized.h (uninitialized_copy)
(uninitialized_fill, uninitialized_fill_n): Add static assertions to
diagnose invalid uses.
* testsuite/20_util/specialized_algorithms/uninitialized_copy/1.cc:
Adjust expected error.
* testsuite/20_util/specialized_algorithms/uninitialized_copy/89164.cc:
New test.
* testsuite/20_util/specialized_algorithms/uninitialized_copy_n/
89164.cc: New test.
* testsuite/20_util/specialized_algorithms/uninitialized_fill/89164.cc:
New test.
* testsuite/20_util/specialized_algorithms/uninitialized_fill_n/
89164.cc: New test.
* testsuite/23_containers/vector/cons/89164.cc: New test.
* testsuite/23_containers/vector/cons/89164_c++17.cc: New test.
From-SVN: r275177
The x86 attributes such as ms_abi, stdcall, fastcall etc. alter the
function type, which means that functions with one of those attributes
do not match any of the partial specializations of std::is_function.
Rather than duplicating the list for every calling convention, use a
much simpler definition of std::is_function.
Also redefine __is_referenceable to not rely on partial specializations
for each type of referenceable function.
PR libstdc++/91371
* include/std/type_traits (is_function): Simplify definition. Remove
partial specializations for function types.
(__is_referenceable): Simplify definition.
* testsuite/20_util/bind/91371.cc: New test.
* testsuite/20_util/is_function/91371.cc: New test.
* testsuite/20_util/is_function/value.cc: Check more pointer types.
* testsuite/20_util/is_member_function_pointer/91371.cc: New test.
* testsuite/20_util/is_object/91371.cc: New test.
From-SVN: r274756
In C++17 a function can return a prvalue of a type that cannot be moved
or copied. The current implementation of std::is_invocable_r uses
std::is_convertible to test the conversion to R required by INVOKE<R>.
That fails for non-copyable prvalues, because std::is_convertible is
defined in terms of std::declval which uses std::add_rvalue_reference.
In C++17 conversion from R to R involves no copies and so is not the
same as conversion from R&& to R.
This commit changes std::is_invocable_r to check the conversion without
using std::is_convertible.
std::function also contains a similar check using std::is_convertible,
which can be fixed by simply reusing std::is_invocable_r (but because
std::is_invocable_r is not defined for C++11 it uses the underlying
std::__is_invocable_impl trait directly).
PR libstdc++/91456
* include/bits/std_function.h (__check_func_return_type): Remove.
(function::_Callable): Use std::__is_invocable_impl instead of
__check_func_return_type.
* include/std/type_traits (__is_invocable_impl): Add another defaulted
template parameter. Define a separate partial specialization for
INVOKE and INVOKE<void>. For INVOKE<R> replace is_convertible check
with a check that models delayed temporary materialization.
* testsuite/20_util/function/91456.cc: New test.
* testsuite/20_util/is_invocable/91456.cc: New test.
From-SVN: r274542
This non-standard extension is redundant and unused by the library.
* include/std/type_traits (__is_nullptr_t): Add deprecated attribute.
From-SVN: r274491
When unpacking a std::tuple we know that the std::get calls are
noexcept, so only the invocation (for std::apply) and construction (for
std::make_from_tuple) can throw.
We also know the std::get calls won't throw for a std::array, but this
patch doesn't specialize the variable template for std::array. For an
arbitrary tuple-like type we don't know if the std::get calls will
throw, and so just use a potentially-throwing noexcept-specifier.
* include/std/tuple (__unpack_std_tuple): New variable template and
partial specializations.
(apply, make_from_tuple): Add noexcept-specifier.
* testsuite/20_util/tuple/apply/2.cc: New test.
* testsuite/20_util/tuple/make_from_tuple/2.cc: New test.
From-SVN: r274312
normal_mv_distribution maintains the variance-covariance matrix param
in Cholesky-decomposed form. Existing param_type constructors, when
taking a full or lower-triangle varcov matrix, perform Cholesky
decomposition to convert it to the internal representation. This
internal representation is visible both in the varcov() result, and in
the streamed-out representation of a normal_mv_distribution object.
The problem is that when that representation is streamed back in, the
read-back decomposed varcov matrix is used as a lower-triangle
non-decomposed varcov matrix, and it undergoes Cholesky decomposition
again. So, each cycle of stream-out/stream-in changes the varcov
matrix to its "square root", instead of restoring the original
params.
This patch includes Corentin's changes that introduce verification in
testsuite/ext/random/normal_mv_distribution/operators/serialize.cc and
other similar tests that the object read back in compares equal to the
written-out object: the modified tests pass only if (u == v).
This patch also fixes the error exposed by his change, introducing an
alternate private constructor for param_type, used only by operator>>.
for libstdc++-v3/ChangeLog
* include/ext/random
(normal_mv_distribution::param_type::param_type): New private
ctor taking a decomposed varcov matrix, for use by...
(operator>>): ... this, befriended.
* include/ext/random.tcc (operator>>): Use it.
(normal_mv_distribution::param_type::_M_init_lower): Adjust
member function name in exception message.
for libstdc++-v3/ChangeLog
from Corentin Gay <gay@adacore.com>
* testsuite/ext/random/beta_distribution/operators/serialize.cc,
testsuite/ext/random/hypergeometric_distribution/operators/serialize.cc,
testsuite/ext/random/normal_mv_distribution/operators/serialize.cc,
testsuite/ext/random/triangular_distribution/operators/serialize.cc,
testsuite/ext/random/von_mises_distribution/operators/serialize.cc:
Add call to `VERIFY`.
From-SVN: r274233
As an extension to what the standard requires, this also adds
conditional noexcept-specifiers to the std::to_array functions.
P0325R4 to_array from LFTS with updates
* include/experimental/array (to_array): Qualify call to __to_array.
* include/std/array (__cpp_lib_to_array, to_array): Define for C++20.
* include/std/version (__cpp_lib_to_array): Likewise.
* testsuite/23_containers/array/creation/1.cc: New test.
* testsuite/23_containers/array/creation/2.cc: New test.
* testsuite/23_containers/array/creation/3_neg.cc: New test.
* testsuite/23_containers/array/tuple_interface/tuple_element_neg.cc:
Use zero for dg-error line number.
From-SVN: r274209
The values of the constants are taken from Glibc where the equivalent
constant exists, or by rounding the actual constant to the same number
of digits as the Glibc constants have.
P0631R4 Math Constants
* include/Makefile.am: Add new header.
* include/Makefile.in: Regenerate.
* include/precompiled/stdc++.h: Include new header.
* include/std/numbers: New header.
* include/std/version (__cpp_lib_math_constants): Define.
* testsuite/26_numerics/numbers/1.cc: New test.
* testsuite/26_numerics/numbers/2.cc: New test.
* testsuite/26_numerics/numbers/3.cc: New test.
* testsuite/26_numerics/numbers/nonfloat_neg.cc: New test.
From-SVN: r273940
PR libstdc++/91308
* include/bits/unique_ptr.h (unique_ptr::__safe_conversion_up): Remove
constraints on deleter that should only apply to the constructor.
(unique_ptr<T[], D>::__safe_conversion_up): Likewise.
(unique_ptr<T[], D>::unique_ptr(unique_ptr<U, D>&&)): Restore
constraints on deleter here.
* testsuite/20_util/unique_ptr/assign/91308.cc: New test.
From-SVN: r273937
This macro was added as part of moving std::endian from <type_traits> to
<bit>.
* include/std/bit (__cpp_lib_endian): Define.
* include/std/version (__cpp_lib_endian): Define.
* testsuite/26_numerics/endian/2.cc: New.
* testsuite/26_numerics/endian/3.cc: New.
* testsuite/26_numerics/endian/4.cc: New.
From-SVN: r273828
This change to an early C++2a feature was just approved (P1612R1).
* include/std/bit (endian): Move definition here as per P1612R1.
* include/std/type_traits (endian): Remove definition from here.
* testsuite/20_util/endian/1.cc: Rename to ...
* testsuite/26_numerics/endian/1.cc: ... here. Adjust header.
From-SVN: r273816
This proposal has now been accepted for C++20, with a few changes. This
patch adjusts std::rotl and std::rotr to match the final specification
and declares the additions for C++2a mode even when __STRICT_ANSI__ is
defined.
* include/std/bit (__rotl, __rotr): Change second parameter from
unsigned int to int and handle negative values.
(rotl, rotr): Remove check for __STRICT_ANSI__. Change second
parameter from unsigned int to int. Add nodiscard attribute.
* testsuite/26_numerics/bit/bitops.rot/rotl.cc: Rename to ...
* testsuite/26_numerics/bit/bit.rotate/rotl.cc: Here. Test negative
shifts.
* testsuite/26_numerics/bit/bitops.rot/rotr.cc: Rename to ...
* testsuite/26_numerics/bit/bit.rotate/rotr.cc: Here. Test negative
shifts.
From-SVN: r273706
* include/std/bit (__ceil2): Make unrepresentable results undefined,
as per P1355R2. Add debug assertion. Perform one left shift, not two,
so that out of range values cause undefined behaviour. Ensure that
shift will still be undefined if left operand is promoted.
* testsuite/26_numerics/bit/bit.pow.two/ceil2.cc: Replace checks for
unrepresentable values with checks that they are not core constant
expressions.
* testsuite/26_numerics/bit/bit.pow.two/ceil2_neg.cc: New test.
From-SVN: r273705
C++20 concepts require parens around atomic constraints that are not
primary-expressions.
* include/std/memory (uses_allocator_construction_args): Add parens
around constraint.
From-SVN: r273515
This defines the equivalent of C++2a's std::type_identity_t alias but
for use in C++11 and later. This can be used to replace __detail::__idt
in the string_view headers, which previously used common_type_t because
the one argument specialization of common_type_t was simply the identity
transform (which is no longer true).
* include/experimental/string_view (__detail::__idt): Remove.
(operator==, operator!=, operator<, operator>, operator<=, operator>=):
Use __type_identity_t instead of __detail::__idt;
* include/std/string_view (__detail::__idt): Remove.
(operator==, operator!=, operator<, operator>, operator<=, operator>=):
Use __type_identity_t instead of __detail::__idt;
* include/std/type_traits (__type_identity_t): New alias template.
From-SVN: r273442
This adds the new atomic types from C++2a, as proposed by P0019 and
P0020. To reduce duplication the calls to the compiler's atomic
built-ins are wrapped in new functions in the __atomic_impl namespace.
These functions are currently only used by std::atomic<floating-point>
and std::atomic_ref but could also be used for all other specializations
of std::atomic.
* include/bits/atomic_base.h (__atomic_impl): New namespace for
wrappers around atomic built-ins.
(__atomic_float, __atomic_ref): New class templates for use as base
classes.
* include/std/atomic (atomic<float>, atomic<double>)
(atomic<long double>): New explicit specializations.
(atomic_ref): New class template.
(__cpp_lib_atomic_ref): Define.
* include/std/version (__cpp_lib_atomic_ref): Define.
* testsuite/29_atomics/atomic/60695.cc: Adjust dg-error.
* testsuite/29_atomics/atomic_float/1.cc: New test.
* testsuite/29_atomics/atomic_float/requirements.cc: New test.
* testsuite/29_atomics/atomic_ref/deduction.cc: New test.
* testsuite/29_atomics/atomic_ref/float.cc: New test.
* testsuite/29_atomics/atomic_ref/generic.cc: New test.
* testsuite/29_atomics/atomic_ref/integral.cc: New test.
* testsuite/29_atomics/atomic_ref/pointer.cc: New test.
* testsuite/29_atomics/atomic_ref/requirements.cc: New test.
From-SVN: r273420
Because the inline versions of __exchange_and_add and __atomic_add are
also marked static, they cannot be used from templates or other inline
functions without ODR violations. This change gives them external
linkage, but adds the always_inline attribute.
* include/ext/atomicity.h [_GLIBCXX_ATOMIC_BUILTINS] (__atomic_add)
(__exchange_and_add): Replace static specifier with always_inline
attribute.
(__exchange_and_add_single, __atomic_add_single): Likewise.
(__exchange_and_add_dispatch, __atomic_add_dispatch): Likewise. Also
combine !__gthread_active_p() and !__GTHREADS branches.
From-SVN: r273144
Clang seems to define built-ins that start with "__builtin_" as
non-keywords, which means that we need to use __has_builtin to detect
them, not __is_identifier. The built-ins that don't start with
"__builtin_" are keywords, and can only be detected using
__is_identifier and not by __has_builtin.
* include/bits/c++config (_GLIBCXX_HAVE_BUILTIN_LAUNDER)
(_GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED): Use __has_builtin
instead of __is_identifier to detect Clang support.
From-SVN: r272931
This type isn't used anywhere yet, but will be needed for the
floating-point overloads of to_chars and from_chars.
* include/std/charconv (chars_format): Define bitmask type.
* testsuite/20_util/to_chars/chars_format.cc: New test.
From-SVN: r272718
Reuse the __is_one_of alias in additional places, and define traits to
check for signed/unsigned integer types so we don't have to duplicate
those checks elsewhere.
The additional overloads for std::byte in <bit> were reviewed by LEWG
and considered undesirable, so this patch removes them.
* include/bits/fs_path.h (path::__is_encoded_char): Use __is_one_of.
* include/std/bit (_If_is_unsigned_integer_type): Remove.
(_If_is_unsigned_integer): Use __is_unsigned_integer.
(rotl(byte, unsigned), rotr(byte, unsigned), countl_zero(byte))
(countl_one(byte), countr_zero(byte), countr_one(byte))
(popcount(byte), ispow2(byte), ceil2(byte), floor2(byte))
(log2p1(byte)): Remove.
* include/std/charconv (__detail::__is_one_of): Move to <type_traits>.
(__detail::__is_int_to_chars_type): Remove.
(__detail::__integer_to_chars_result_type): Use __is_signed_integer
and __is_unsigned_integer.
* include/std/type_traits (__is_one_of): Move here from <charconv>.
(__is_signed_integer, __is_unsigned_integer): New helpers.
* testsuite/26_numerics/bit/bit.pow.two/ceil2.cc: Remove test for
std::byte overload.
* testsuite/26_numerics/bit/bit.pow.two/floor2.cc: Likewise.
* testsuite/26_numerics/bit/bit.pow.two/ispow2.cc: Likewise.
* testsuite/26_numerics/bit/bit.pow.two/log2p1.cc: Likewise.
* testsuite/26_numerics/bit/bitops.count/countl_one.cc: Likewise.
* testsuite/26_numerics/bit/bitops.count/countl_zero.cc: Likewise.
* testsuite/26_numerics/bit/bitops.count/countr_one.cc: Likewise.
* testsuite/26_numerics/bit/bitops.count/countr_zero.cc: Likewise.
* testsuite/26_numerics/bit/bitops.count/popcount.cc: Likewise.
* testsuite/26_numerics/bit/bitops.rot/rotl.cc: Likewise.
* testsuite/26_numerics/bit/bitops.rot/rotr.cc: Likewise.
From-SVN: r272695
Although libstdc++ adds 'constexpr' to its std::abs(floating-point)
overloads (as a non-conforming extension), those overloads are not used
if the target libc provides them, which is the case on Solaris.
The fix is to avoid std::abs and simply apply the negation when needed.
* include/std/numeric (midpoint(T, T)): Avoid std::abs in constexpr
function.
From-SVN: r272653
* include/pstl/pstl_config.h (_PSTL_PRAGMA_SIMD_SCAN,
_PSTL_PRAGMA_SIMD_INCLUSIVE_SCAN, _PSTL_PRAGMA_SIMD_EXCLUSIVE_SCAN):
Define to OpenMP 5.0 pragmas even for GCC 10.0+.
(_PSTL_UDS_PRESENT): Define to 1 for GCC 10.0+.
From-SVN: r272634
The current implementation of istream_iterator allows the iterator to be
reused after reaching end-of-stream, so that subsequent reads from the
stream can succeed (e.g. if the stream state has been cleared and stream
position changed from EOF). The P0738R2 paper clarified that the
expected behaviour is to set the stream pointer to null after reaching
end-of-stream, preventing further reads.
This implements that requirement, and adds the new default constructor
to std::ostream_iterator.
* include/bits/stream_iterator.h (istream_iterator::_M_equal()): Make
private.
(istream_iterator::_M_read()): Do not check stream state before
attempting extraction. Set stream pointer to null when extraction
fails (P0738R2).
(operator==(const istream_iterator&, const istream_iterator&)): Change
to be a hidden friend of istream_iterator.
(operator!=(const istream_iterator&, const istream_iterator&)):
Likewise.
(ostream_iterator::ostream_iterator()): Add default constructor.
(ostream_iterator::ostream_iterator(ostream_type*, const C*)): Use
addressof.
* testsuite/24_iterators/istream_iterator/1.cc: New test.
* testsuite/24_iterators/ostream_iterator/1.cc: New test.
* testsuite/24_iterators/ostream_iterator/70766.cc: Also check
constructor taking a string.
* testsuite/24_iterators/ostream_iterator/requirements/constexpr.cc:
New test.
From-SVN: r272491
The change in r263433 broke the contract of the __rotate functions, by no
longer accepting empty ranges. That means that callers which inlined the
old version of std::rotate (without checks) that end up linking to a new
definition of std::__rotate (also without checks) could perform a divide
by zero and crash.
This restores the old contract of the __rotate overloads.
PR libstdc++/90920 partially revert r263433
* include/bits/stl_algo.h (__rotate): Restore checks for empty ranges.
(rotate): Remove checks.
* testsuite/25_algorithms/rotate/90920.cc: New test.
From-SVN: r272489
