Implement the non-parallel versions of exclusive_scan and transform_exclusive_scan. Reviewed as https://reviews.llvm.org/D34038.
llvm-svn: 305136
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: e948ba1cd18f64f4a0bd5d534ddd0093d34cf245
diff --git a/include/numeric b/include/numeric
index 0e53ba3..a84fb86 100644
--- a/include/numeric
+++ b/include/numeric
@@ -42,6 +42,23 @@
OutputIterator
partial_sum(InputIterator first, InputIterator last, OutputIterator result, BinaryOperation binary_op);
+template<class InputIterator, class OutputIterator, class T>
+ OutputIterator
+ exclusive_scan(InputIterator first, InputIterator last,
+ OutputIterator result, T init); // C++17
+
+template<class InputIterator, class OutputIterator, class T, class BinaryOperation>
+ OutputIterator
+ exclusive_scan(InputIterator first, InputIterator last,
+ OutputIterator result, T init, BinaryOperation binary_op); // C++17
+
+template<class InputIterator, class OutputIterator, class T,
+ class BinaryOperation, class UnaryOperation>
+ OutputIterator
+ transform_exclusive_scan(InputIterator first, InputIterator last,
+ OutputIterator result, T init,
+ BinaryOperation binary_op, UnaryOperation unary_op); // C++17
+
template <class InputIterator, class OutputIterator>
OutputIterator
adjacent_difference(InputIterator first, InputIterator last, OutputIterator result);
@@ -66,6 +83,7 @@
#include <__config>
#include <iterator>
#include <limits> // for numeric_limits
+#include <functional>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
@@ -154,6 +172,59 @@
return __result;
}
+#if _LIBCPP_STD_VER > 14
+template <class _InputIterator, class _OutputIterator, class _Tp, class _BinaryOp>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+exclusive_scan(_InputIterator __first, _InputIterator __last,
+ _OutputIterator __result, _Tp __init, _BinaryOp __b)
+{
+ if (__first != __last)
+ {
+ _Tp __saved = __init;
+ do
+ {
+ __init = __b(__init, *__first);
+ *__result = __saved;
+ __saved = __init;
+ ++__result;
+ } while (++__first != __last);
+ }
+ return __result;
+}
+
+template <class _InputIterator, class _OutputIterator, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+exclusive_scan(_InputIterator __first, _InputIterator __last,
+ _OutputIterator __result, _Tp __init)
+{
+ return _VSTD::exclusive_scan(__first, __last, __result, __init, _VSTD::plus<>());
+}
+
+template <class _InputIterator, class _OutputIterator, class _Tp,
+ class _BinaryOp, class _UnaryOp>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+transform_exclusive_scan(_InputIterator __first, _InputIterator __last,
+ _OutputIterator __result, _Tp __init,
+ _BinaryOp __b, _UnaryOp __u)
+{
+ if (__first != __last)
+ {
+ _Tp __saved = __init;
+ do
+ {
+ __init = __b(__init, __u(*__first));
+ *__result = __saved;
+ __saved = __init;
+ ++__result;
+ } while (++__first != __last);
+ }
+ return __result;
+}
+#endif
+
template <class _InputIterator, class _OutputIterator>
inline _LIBCPP_INLINE_VISIBILITY
_OutputIterator