* [PATCH] libstdc++: Mark some more algorithms constexpr for C++20
@ 2020-09-19 1:08 Patrick Palka
2020-09-19 1:08 ` [PATCH] libstdc++: Fix division by zero in std::sample Patrick Palka
2020-09-21 14:52 ` [PATCH] libstdc++: Mark some more algorithms constexpr for C++20 Jonathan Wakely
0 siblings, 2 replies; 7+ messages in thread
From: Patrick Palka @ 2020-09-19 1:08 UTC (permalink / raw)
To: gcc-patches; +Cc: libstdc++, Patrick Palka
As per P0202.
Tested on x86_64-pc-linux-gnu.
libstdc++-v3/ChangeLog:
* include/bits/stl_algo.h (for_each_n): Mark constexpr for C++20.
(search): Likewise for the overload that takes a searcher.
* testsuite/25_algorithms/for_each/constexpr.cc: Test constexpr
std::for_each_n.
* testsuite/25_algorithms/search/constexpr.cc: Test constexpr
std::search overload that takes a searcher.
---
libstdc++-v3/include/bits/stl_algo.h | 2 ++
.../testsuite/25_algorithms/for_each/constexpr.cc | 12 ++++++++++++
.../testsuite/25_algorithms/search/constexpr.cc | 4 ++++
3 files changed, 18 insertions(+)
diff --git a/libstdc++-v3/include/bits/stl_algo.h b/libstdc++-v3/include/bits/stl_algo.h
index 550a15f2b3b..a0b96c61798 100644
--- a/libstdc++-v3/include/bits/stl_algo.h
+++ b/libstdc++-v3/include/bits/stl_algo.h
@@ -3832,6 +3832,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
* If `__f` has a return value it is ignored.
*/
template<typename _InputIterator, typename _Size, typename _Function>
+ _GLIBCXX20_CONSTEXPR
_InputIterator
for_each_n(_InputIterator __first, _Size __n, _Function __f)
{
@@ -4251,6 +4252,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
* @return @p __searcher(__first,__last).first
*/
template<typename _ForwardIterator, typename _Searcher>
+ _GLIBCXX20_CONSTEXPR
inline _ForwardIterator
search(_ForwardIterator __first, _ForwardIterator __last,
const _Searcher& __searcher)
diff --git a/libstdc++-v3/testsuite/25_algorithms/for_each/constexpr.cc b/libstdc++-v3/testsuite/25_algorithms/for_each/constexpr.cc
index 1bece35a0d9..b3aca23eccc 100644
--- a/libstdc++-v3/testsuite/25_algorithms/for_each/constexpr.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/for_each/constexpr.cc
@@ -34,3 +34,15 @@ test()
}
static_assert(test());
+
+constexpr bool
+test_n()
+{
+ int tot = 0;
+ auto sum = [&total = tot](int i){ total += i; };
+ auto sum2 = std::for_each_n(ca0.begin(), std::size(ca0)-1, sum);
+
+ return tot == 55;
+}
+
+static_assert(test_n());
diff --git a/libstdc++-v3/testsuite/25_algorithms/search/constexpr.cc b/libstdc++-v3/testsuite/25_algorithms/search/constexpr.cc
index ba9437eced7..e34194cfc5d 100644
--- a/libstdc++-v3/testsuite/25_algorithms/search/constexpr.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/search/constexpr.cc
@@ -31,6 +31,10 @@ test()
cam.begin(), cam.end(),
std::equal_to<int>());
+ const auto outtt2
+ = std::search(ca0.begin(), ca0.end(),
+ std::default_searcher(cam.begin(), cam.end()));
+
return true;
}
--
2.28.0.497.g54e85e7af1
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH] libstdc++: Fix division by zero in std::sample
2020-09-19 1:08 [PATCH] libstdc++: Mark some more algorithms constexpr for C++20 Patrick Palka
@ 2020-09-19 1:08 ` Patrick Palka
2020-09-21 12:46 ` Patrick Palka
2020-09-21 15:01 ` Jonathan Wakely
2020-09-21 14:52 ` [PATCH] libstdc++: Mark some more algorithms constexpr for C++20 Jonathan Wakely
1 sibling, 2 replies; 7+ messages in thread
From: Patrick Palka @ 2020-09-19 1:08 UTC (permalink / raw)
To: gcc-patches; +Cc: libstdc++, Patrick Palka
This fixes a division by zero in the selection-sampling std::__search
overload when the input range is empty (and hence __unsampled_sz is 0).
Tested on x86_64-pc-linux-gnu.
libstdc++-v3/ChangeLog:
* include/bits/stl_algo.h (__sample): Exit early when the
input range is empty.
* testsuite/25_algorithms/sample/3.cc: New test.
---
libstdc++-v3/include/bits/stl_algo.h | 3 ++
.../testsuite/25_algorithms/sample/3.cc | 50 +++++++++++++++++++
2 files changed, 53 insertions(+)
create mode 100644 libstdc++-v3/testsuite/25_algorithms/sample/3.cc
diff --git a/libstdc++-v3/include/bits/stl_algo.h b/libstdc++-v3/include/bits/stl_algo.h
index a0b96c61798..2478b5857c1 100644
--- a/libstdc++-v3/include/bits/stl_algo.h
+++ b/libstdc++-v3/include/bits/stl_algo.h
@@ -5775,6 +5775,9 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
using _Gen = remove_reference_t<_UniformRandomBitGenerator>;
using __uc_type = common_type_t<typename _Gen::result_type, _USize>;
+ if (__first == __last)
+ return __out;
+
__distrib_type __d{};
_Size __unsampled_sz = std::distance(__first, __last);
__n = std::min(__n, __unsampled_sz);
diff --git a/libstdc++-v3/testsuite/25_algorithms/sample/3.cc b/libstdc++-v3/testsuite/25_algorithms/sample/3.cc
new file mode 100644
index 00000000000..e89c40e27ee
--- /dev/null
+++ b/libstdc++-v3/testsuite/25_algorithms/sample/3.cc
@@ -0,0 +1,50 @@
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do run { target c++17 } }
+// { dg-require-cstdint "" }
+
+#include <algorithm>
+#include <random>
+#include <testsuite_hooks.h>
+#include <testsuite_iterators.h>
+
+std::mt19937 rng;
+
+using std::sample;
+using __gnu_test::test_container;
+using __gnu_test::output_iterator_wrapper;
+using __gnu_test::forward_iterator_wrapper;
+
+void
+test01()
+{
+ const int in = 0;
+ test_container<const int, forward_iterator_wrapper> pop(&in, &in);
+ int out;
+ test_container<int, output_iterator_wrapper> samp(&out, &out + 1);
+
+ auto it = sample(pop.begin(), pop.end(), samp.begin(), 1, rng);
+ VERIFY( it.ptr == &out );
+}
+
+int
+main()
+{
+ test01();
+}
--
2.28.0.497.g54e85e7af1
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] libstdc++: Fix division by zero in std::sample
2020-09-19 1:08 ` [PATCH] libstdc++: Fix division by zero in std::sample Patrick Palka
@ 2020-09-21 12:46 ` Patrick Palka
2020-09-21 15:01 ` Jonathan Wakely
1 sibling, 0 replies; 7+ messages in thread
From: Patrick Palka @ 2020-09-21 12:46 UTC (permalink / raw)
To: Patrick Palka; +Cc: gcc-patches, libstdc++
On Fri, 18 Sep 2020, Patrick Palka wrote:
> This fixes a division by zero in the selection-sampling std::__search
Whoops, this line say std::__sample, not std::__search.
> overload when the input range is empty (and hence __unsampled_sz is 0).
>
> Tested on x86_64-pc-linux-gnu.
>
> libstdc++-v3/ChangeLog:
>
> * include/bits/stl_algo.h (__sample): Exit early when the
> input range is empty.
> * testsuite/25_algorithms/sample/3.cc: New test.
> ---
> libstdc++-v3/include/bits/stl_algo.h | 3 ++
> .../testsuite/25_algorithms/sample/3.cc | 50 +++++++++++++++++++
> 2 files changed, 53 insertions(+)
> create mode 100644 libstdc++-v3/testsuite/25_algorithms/sample/3.cc
>
> diff --git a/libstdc++-v3/include/bits/stl_algo.h b/libstdc++-v3/include/bits/stl_algo.h
> index a0b96c61798..2478b5857c1 100644
> --- a/libstdc++-v3/include/bits/stl_algo.h
> +++ b/libstdc++-v3/include/bits/stl_algo.h
> @@ -5775,6 +5775,9 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
> using _Gen = remove_reference_t<_UniformRandomBitGenerator>;
> using __uc_type = common_type_t<typename _Gen::result_type, _USize>;
>
> + if (__first == __last)
> + return __out;
> +
> __distrib_type __d{};
> _Size __unsampled_sz = std::distance(__first, __last);
> __n = std::min(__n, __unsampled_sz);
> diff --git a/libstdc++-v3/testsuite/25_algorithms/sample/3.cc b/libstdc++-v3/testsuite/25_algorithms/sample/3.cc
> new file mode 100644
> index 00000000000..e89c40e27ee
> --- /dev/null
> +++ b/libstdc++-v3/testsuite/25_algorithms/sample/3.cc
> @@ -0,0 +1,50 @@
> +// Copyright (C) 2020 Free Software Foundation, Inc.
> +//
> +// This file is part of the GNU ISO C++ Library. This library is free
> +// software; you can redistribute it and/or modify it under the
> +// terms of the GNU General Public License as published by the
> +// Free Software Foundation; either version 3, or (at your option)
> +// any later version.
> +
> +// This library is distributed in the hope that it will be useful,
> +// but WITHOUT ANY WARRANTY; without even the implied warranty of
> +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> +// GNU General Public License for more details.
> +
> +// You should have received a copy of the GNU General Public License along
> +// with this library; see the file COPYING3. If not see
> +// <http://www.gnu.org/licenses/>.
> +
> +// { dg-options "-std=gnu++17" }
> +// { dg-do run { target c++17 } }
> +// { dg-require-cstdint "" }
> +
> +#include <algorithm>
> +#include <random>
> +#include <testsuite_hooks.h>
> +#include <testsuite_iterators.h>
> +
> +std::mt19937 rng;
> +
> +using std::sample;
> +using __gnu_test::test_container;
> +using __gnu_test::output_iterator_wrapper;
> +using __gnu_test::forward_iterator_wrapper;
> +
> +void
> +test01()
> +{
> + const int in = 0;
> + test_container<const int, forward_iterator_wrapper> pop(&in, &in);
> + int out;
> + test_container<int, output_iterator_wrapper> samp(&out, &out + 1);
> +
> + auto it = sample(pop.begin(), pop.end(), samp.begin(), 1, rng);
> + VERIFY( it.ptr == &out );
> +}
> +
> +int
> +main()
> +{
> + test01();
> +}
> --
> 2.28.0.497.g54e85e7af1
>
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] libstdc++: Mark some more algorithms constexpr for C++20
2020-09-19 1:08 [PATCH] libstdc++: Mark some more algorithms constexpr for C++20 Patrick Palka
2020-09-19 1:08 ` [PATCH] libstdc++: Fix division by zero in std::sample Patrick Palka
@ 2020-09-21 14:52 ` Jonathan Wakely
1 sibling, 0 replies; 7+ messages in thread
From: Jonathan Wakely @ 2020-09-21 14:52 UTC (permalink / raw)
To: Patrick Palka; +Cc: gcc-patches, libstdc++
On 18/09/20 21:08 -0400, Patrick Palka via Libstdc++ wrote:
>As per P0202.
>
>Tested on x86_64-pc-linux-gnu.
>
>libstdc++-v3/ChangeLog:
>
> * include/bits/stl_algo.h (for_each_n): Mark constexpr for C++20.
> (search): Likewise for the overload that takes a searcher.
> * testsuite/25_algorithms/for_each/constexpr.cc: Test constexpr
> std::for_each_n.
> * testsuite/25_algorithms/search/constexpr.cc: Test constexpr
> std::search overload that takes a searcher.
>---
> libstdc++-v3/include/bits/stl_algo.h | 2 ++
> .../testsuite/25_algorithms/for_each/constexpr.cc | 12 ++++++++++++
> .../testsuite/25_algorithms/search/constexpr.cc | 4 ++++
> 3 files changed, 18 insertions(+)
OK, thanks.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] libstdc++: Fix division by zero in std::sample
2020-09-19 1:08 ` [PATCH] libstdc++: Fix division by zero in std::sample Patrick Palka
2020-09-21 12:46 ` Patrick Palka
@ 2020-09-21 15:01 ` Jonathan Wakely
2020-10-20 17:02 ` Jonathan Wakely
1 sibling, 1 reply; 7+ messages in thread
From: Jonathan Wakely @ 2020-09-21 15:01 UTC (permalink / raw)
To: Patrick Palka; +Cc: gcc-patches, libstdc++
On 18/09/20 21:08 -0400, Patrick Palka via Libstdc++ wrote:
>This fixes a division by zero in the selection-sampling std::__search
>overload when the input range is empty (and hence __unsampled_sz is 0).
>
>Tested on x86_64-pc-linux-gnu.
>
>libstdc++-v3/ChangeLog:
>
> * include/bits/stl_algo.h (__sample): Exit early when the
> input range is empty.
> * testsuite/25_algorithms/sample/3.cc: New test.
>---
> libstdc++-v3/include/bits/stl_algo.h | 3 ++
> .../testsuite/25_algorithms/sample/3.cc | 50 +++++++++++++++++++
> 2 files changed, 53 insertions(+)
> create mode 100644 libstdc++-v3/testsuite/25_algorithms/sample/3.cc
OK, thanks.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] libstdc++: Fix division by zero in std::sample
2020-09-21 15:01 ` Jonathan Wakely
@ 2020-10-20 17:02 ` Jonathan Wakely
2020-10-20 17:36 ` Patrick Palka
0 siblings, 1 reply; 7+ messages in thread
From: Jonathan Wakely @ 2020-10-20 17:02 UTC (permalink / raw)
To: Patrick Palka; +Cc: gcc-patches, libstdc++
On 21/09/20 16:01 +0100, Jonathan Wakely wrote:
>On 18/09/20 21:08 -0400, Patrick Palka via Libstdc++ wrote:
>>This fixes a division by zero in the selection-sampling std::__search
>>overload when the input range is empty (and hence __unsampled_sz is 0).
>>
>>Tested on x86_64-pc-linux-gnu.
>>
>>libstdc++-v3/ChangeLog:
>>
>> * include/bits/stl_algo.h (__sample): Exit early when the
>> input range is empty.
>> * testsuite/25_algorithms/sample/3.cc: New test.
>>---
>>libstdc++-v3/include/bits/stl_algo.h | 3 ++
>>.../testsuite/25_algorithms/sample/3.cc | 50 +++++++++++++++++++
>>2 files changed, 53 insertions(+)
>>create mode 100644 libstdc++-v3/testsuite/25_algorithms/sample/3.cc
>
>OK, thanks.
Could you please backport this to all branches too.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] libstdc++: Fix division by zero in std::sample
2020-10-20 17:02 ` Jonathan Wakely
@ 2020-10-20 17:36 ` Patrick Palka
0 siblings, 0 replies; 7+ messages in thread
From: Patrick Palka @ 2020-10-20 17:36 UTC (permalink / raw)
To: Jonathan Wakely; +Cc: Patrick Palka, gcc-patches, libstdc++
On Tue, 20 Oct 2020, Jonathan Wakely wrote:
> On 21/09/20 16:01 +0100, Jonathan Wakely wrote:
> > On 18/09/20 21:08 -0400, Patrick Palka via Libstdc++ wrote:
> > > This fixes a division by zero in the selection-sampling std::__search
> > > overload when the input range is empty (and hence __unsampled_sz is 0).
> > >
> > > Tested on x86_64-pc-linux-gnu.
> > >
> > > libstdc++-v3/ChangeLog:
> > >
> > > * include/bits/stl_algo.h (__sample): Exit early when the
> > > input range is empty.
> > > * testsuite/25_algorithms/sample/3.cc: New test.
> > > ---
> > > libstdc++-v3/include/bits/stl_algo.h | 3 ++
> > > .../testsuite/25_algorithms/sample/3.cc | 50 +++++++++++++++++++
> > > 2 files changed, 53 insertions(+)
> > > create mode 100644 libstdc++-v3/testsuite/25_algorithms/sample/3.cc
> >
> > OK, thanks.
>
> Could you please backport this to all branches too.
Ah yes, sorry about losing track of this patch. I should be able to get
the backports done by end of today.
^ permalink raw reply [flat|nested] 7+ messages in thread
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2020-09-19 1:08 [PATCH] libstdc++: Mark some more algorithms constexpr for C++20 Patrick Palka
2020-09-19 1:08 ` [PATCH] libstdc++: Fix division by zero in std::sample Patrick Palka
2020-09-21 12:46 ` Patrick Palka
2020-09-21 15:01 ` Jonathan Wakely
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2020-09-21 14:52 ` [PATCH] libstdc++: Mark some more algorithms constexpr for C++20 Jonathan Wakely
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