[PATCH] libstdc++: P1645R1 constexpr for <numeric> algorithms
Jonathan Wakely
jwakely@redhat.com
Wed Feb 26 14:30:00 GMT 2020
On 25/02/20 15:36 -0500, Patrick Palka wrote:
>This adds constexpr to 11 algorithms defined in <numeric> as per P1645R1.
>
>Tested on x86_64-pc-linux-gnu, OK to commit?
>
>libstdc++-v3/ChangeLog:
>
> P1645R1 constexpr for <numeric> algorithms
> * include/bits/stl_numeric.h (iota, accumulate, inner_product,
> partial_sum, adjacent_difference): Make conditionally constexpr for
> C++20.
> * include/std/numeric (reduce, transform_reduce, exclusive_scan,
> inclusive_scan, transform_exclusive_scan, transform_inclusive_scan):
> Likewise. Define the feature test macro __cpp_lib_constexpr_numeric.
> * testsuite/26_numerics/accumulate/constexpr.cc: New test.
> * testsuite/26_numerics/adjacent_difference/constexpr.cc: Likewise.
> * testsuite/26_numerics/exclusive_scan/constexpr.cc: Likewise.
> * testsuite/26_numerics/inclusive_scan/constexpr.cc: Likewise.
> * testsuite/26_numerics/inner_product/constexpr.cc: Likewise.
> * testsuite/26_numerics/iota/constexpr.cc: Likewise.
> * testsuite/26_numerics/partial_sum/constexpr.cc: Likewise.
> * testsuite/26_numerics/reduce/constexpr.cc: Likewise.
> * testsuite/26_numerics/transform_exclusive_scan/constexpr.cc: Likewise.
> * testsuite/26_numerics/transform_inclusive_scan/constexpr.cc: Likewise.
> * testsuite/26_numerics/transform_reduce/constexpr.cc: Likewise.
>---
> libstdc++-v3/include/bits/stl_numeric.h | 9 +++
> libstdc++-v3/include/std/numeric | 18 ++++++
> .../26_numerics/accumulate/constexpr.cc | 42 ++++++++++++++
> .../adjacent_difference/constexpr.cc | 44 +++++++++++++++
> .../26_numerics/exclusive_scan/constexpr.cc | 44 +++++++++++++++
> .../26_numerics/inclusive_scan/constexpr.cc | 55 +++++++++++++++++++
> .../26_numerics/inner_product/constexpr.cc | 45 +++++++++++++++
> .../testsuite/26_numerics/iota/constexpr.cc | 31 +++++++++++
> .../26_numerics/partial_sum/constexpr.cc | 44 +++++++++++++++
> .../testsuite/26_numerics/reduce/constexpr.cc | 52 ++++++++++++++++++
> .../transform_exclusive_scan/constexpr.cc | 33 +++++++++++
> .../transform_inclusive_scan/constexpr.cc | 44 +++++++++++++++
> .../26_numerics/transform_reduce/constexpr.cc | 55 +++++++++++++++++++
> 13 files changed, 516 insertions(+)
> create mode 100644 libstdc++-v3/testsuite/26_numerics/accumulate/constexpr.cc
> create mode 100644 libstdc++-v3/testsuite/26_numerics/adjacent_difference/constexpr.cc
> create mode 100644 libstdc++-v3/testsuite/26_numerics/exclusive_scan/constexpr.cc
> create mode 100644 libstdc++-v3/testsuite/26_numerics/inclusive_scan/constexpr.cc
> create mode 100644 libstdc++-v3/testsuite/26_numerics/inner_product/constexpr.cc
> create mode 100644 libstdc++-v3/testsuite/26_numerics/iota/constexpr.cc
> create mode 100644 libstdc++-v3/testsuite/26_numerics/partial_sum/constexpr.cc
> create mode 100644 libstdc++-v3/testsuite/26_numerics/reduce/constexpr.cc
> create mode 100644 libstdc++-v3/testsuite/26_numerics/transform_exclusive_scan/constexpr.cc
> create mode 100644 libstdc++-v3/testsuite/26_numerics/transform_inclusive_scan/constexpr.cc
> create mode 100644 libstdc++-v3/testsuite/26_numerics/transform_reduce/constexpr.cc
>
>diff --git a/libstdc++-v3/include/bits/stl_numeric.h b/libstdc++-v3/include/bits/stl_numeric.h
>index dd4683fe92e..f95c86a0d48 100644
>--- a/libstdc++-v3/include/bits/stl_numeric.h
>+++ b/libstdc++-v3/include/bits/stl_numeric.h
>@@ -83,6 +83,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> * @ingroup numeric_ops
> */
> template<typename _ForwardIterator, typename _Tp>
>+ _GLIBCXX20_CONSTEXPR
> void
> iota(_ForwardIterator __first, _ForwardIterator __last, _Tp __value)
> {
>@@ -128,6 +129,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
> * @return The final sum.
> */
> template<typename _InputIterator, typename _Tp>
>+ _GLIBCXX20_CONSTEXPR
> inline _Tp
> accumulate(_InputIterator __first, _InputIterator __last, _Tp __init)
> {
>@@ -154,6 +156,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
> * @return The final sum.
> */
> template<typename _InputIterator, typename _Tp, typename _BinaryOperation>
>+ _GLIBCXX20_CONSTEXPR
> inline _Tp
> accumulate(_InputIterator __first, _InputIterator __last, _Tp __init,
> _BinaryOperation __binary_op)
>@@ -182,6 +185,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
> * @return The final inner product.
> */
> template<typename _InputIterator1, typename _InputIterator2, typename _Tp>
>+ _GLIBCXX20_CONSTEXPR
> inline _Tp
> inner_product(_InputIterator1 __first1, _InputIterator1 __last1,
> _InputIterator2 __first2, _Tp __init)
>@@ -214,6 +218,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
> */
> template<typename _InputIterator1, typename _InputIterator2, typename _Tp,
> typename _BinaryOperation1, typename _BinaryOperation2>
>+ _GLIBCXX20_CONSTEXPR
> inline _Tp
> inner_product(_InputIterator1 __first1, _InputIterator1 __last1,
> _InputIterator2 __first2, _Tp __init,
>@@ -246,6 +251,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
> * @return Iterator pointing just beyond the values written to __result.
> */
> template<typename _InputIterator, typename _OutputIterator>
>+ _GLIBCXX20_CONSTEXPR
> _OutputIterator
> partial_sum(_InputIterator __first, _InputIterator __last,
> _OutputIterator __result)
>@@ -287,6 +293,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
> */
> template<typename _InputIterator, typename _OutputIterator,
> typename _BinaryOperation>
>+ _GLIBCXX20_CONSTEXPR
> _OutputIterator
> partial_sum(_InputIterator __first, _InputIterator __last,
> _OutputIterator __result, _BinaryOperation __binary_op)
>@@ -326,6 +333,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
> * DR 539. partial_sum and adjacent_difference should mention requirements
> */
> template<typename _InputIterator, typename _OutputIterator>
>+ _GLIBCXX20_CONSTEXPR
> _OutputIterator
> adjacent_difference(_InputIterator __first,
> _InputIterator __last, _OutputIterator __result)
>@@ -369,6 +377,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
> */
> template<typename _InputIterator, typename _OutputIterator,
> typename _BinaryOperation>
>+ _GLIBCXX20_CONSTEXPR
> _OutputIterator
> adjacent_difference(_InputIterator __first, _InputIterator __last,
> _OutputIterator __result, _BinaryOperation __binary_op)
>diff --git a/libstdc++-v3/include/std/numeric b/libstdc++-v3/include/std/numeric
>index cf35191cb47..8a7830ffd85 100644
>--- a/libstdc++-v3/include/std/numeric
>+++ b/libstdc++-v3/include/std/numeric
>@@ -249,6 +249,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> * arithmetic) the result can be different.
> */
> template<typename _InputIterator, typename _Tp, typename _BinaryOperation>
>+ _GLIBCXX20_CONSTEXPR
> _Tp
> reduce(_InputIterator __first, _InputIterator __last, _Tp __init,
> _BinaryOperation __binary_op)
>@@ -284,6 +285,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> * Equivalent to calling `std::reduce(first, last, init, std::plus<>())`.
> */
> template<typename _InputIterator, typename _Tp>
>+ _GLIBCXX20_CONSTEXPR
> inline _Tp
> reduce(_InputIterator __first, _InputIterator __last, _Tp __init)
> { return std::reduce(__first, __last, std::move(__init), plus<>()); }
>@@ -300,6 +302,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> * Equivalent to calling `std::reduce(first, last, T{}, std::plus<>())`.
> */
> template<typename _InputIterator>
>+ _GLIBCXX20_CONSTEXPR
> inline typename iterator_traits<_InputIterator>::value_type
> reduce(_InputIterator __first, _InputIterator __last)
> {
>@@ -327,6 +330,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> */
> template<typename _InputIterator1, typename _InputIterator2, typename _Tp,
> typename _BinaryOperation1, typename _BinaryOperation2>
>+ _GLIBCXX20_CONSTEXPR
> _Tp
> transform_reduce(_InputIterator1 __first1, _InputIterator1 __last1,
> _InputIterator2 __first2, _Tp __init,
>@@ -369,6 +373,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> * elements.
> */
> template<typename _InputIterator1, typename _InputIterator2, typename _Tp>
>+ _GLIBCXX20_CONSTEXPR
> inline _Tp
> transform_reduce(_InputIterator1 __first1, _InputIterator1 __last1,
> _InputIterator2 __first2, _Tp __init)
>@@ -394,6 +399,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> */
> template<typename _InputIterator, typename _Tp,
> typename _BinaryOperation, typename _UnaryOperation>
>+ _GLIBCXX20_CONSTEXPR
> _Tp
> transform_reduce(_InputIterator __first, _InputIterator __last, _Tp __init,
> _BinaryOperation __binary_op, _UnaryOperation __unary_op)
>@@ -436,6 +442,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> */
> template<typename _InputIterator, typename _OutputIterator, typename _Tp,
> typename _BinaryOperation>
>+ _GLIBCXX20_CONSTEXPR
> _OutputIterator
> exclusive_scan(_InputIterator __first, _InputIterator __last,
> _OutputIterator __result, _Tp __init,
>@@ -469,6 +476,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> * so the Nth input element is not included.
> */
> template<typename _InputIterator, typename _OutputIterator, typename _Tp>
>+ _GLIBCXX20_CONSTEXPR
> inline _OutputIterator
> exclusive_scan(_InputIterator __first, _InputIterator __last,
> _OutputIterator __result, _Tp __init)
>@@ -497,6 +505,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> */
> template<typename _InputIterator, typename _OutputIterator,
> typename _BinaryOperation, typename _Tp>
>+ _GLIBCXX20_CONSTEXPR
> _OutputIterator
> inclusive_scan(_InputIterator __first, _InputIterator __last,
> _OutputIterator __result, _BinaryOperation __binary_op,
>@@ -525,6 +534,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> */
> template<typename _InputIterator, typename _OutputIterator,
> typename _BinaryOperation>
>+ _GLIBCXX20_CONSTEXPR
> _OutputIterator
> inclusive_scan(_InputIterator __first, _InputIterator __last,
> _OutputIterator __result, _BinaryOperation __binary_op)
>@@ -557,6 +567,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> * so the Nth input element is included.
> */
> template<typename _InputIterator, typename _OutputIterator>
>+ _GLIBCXX20_CONSTEXPR
> inline _OutputIterator
> inclusive_scan(_InputIterator __first, _InputIterator __last,
> _OutputIterator __result)
>@@ -584,6 +595,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> */
> template<typename _InputIterator, typename _OutputIterator, typename _Tp,
> typename _BinaryOperation, typename _UnaryOperation>
>+ _GLIBCXX20_CONSTEXPR
> _OutputIterator
> transform_exclusive_scan(_InputIterator __first, _InputIterator __last,
> _OutputIterator __result, _Tp __init,
>@@ -622,6 +634,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> */
> template<typename _InputIterator, typename _OutputIterator,
> typename _BinaryOperation, typename _UnaryOperation, typename _Tp>
>+ _GLIBCXX20_CONSTEXPR
> _OutputIterator
> transform_inclusive_scan(_InputIterator __first, _InputIterator __last,
> _OutputIterator __result,
>@@ -655,6 +668,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> */
> template<typename _InputIterator, typename _OutputIterator,
> typename _BinaryOperation, typename _UnaryOperation>
>+ _GLIBCXX20_CONSTEXPR
> _OutputIterator
> transform_inclusive_scan(_InputIterator __first, _InputIterator __last,
> _OutputIterator __result,
>@@ -676,6 +690,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>
> // @} group numeric_ops
>
>+#if __cplusplus > 201703L
>+#define __cpp_lib_constexpr_numeric 201911L
>+#endif
Please put this before the algos rather than after them, and please
also add it to <version> (in the _GLIBCXX_HOSTED section for C++20
macros).
OK for master with those changes.
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