Implement C++17 std::sample. This patch implements the std::sample function added to C++17 from LFTS. It also removes the std::experimental::sample implementation which now forwards to std::sample. git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@279948 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/experimental/algorithm b/include/experimental/algorithm index 10eafbd..392ca1f 100644 --- a/include/experimental/algorithm +++ b/include/experimental/algorithm
@@ -58,64 +58,11 @@ template <class _PopulationIterator, class _SampleIterator, class _Distance, class _UniformRandomNumberGenerator> -_LIBCPP_INLINE_VISIBILITY -_SampleIterator __sample(_PopulationIterator __first, - _PopulationIterator __last, _SampleIterator __out, - _Distance __n, - _UniformRandomNumberGenerator &&__g, - input_iterator_tag) { - - _Distance __k = 0; - for (; __first != __last && __k < __n; ++__first, (void)++__k) - __out[__k] = *__first; - _Distance __sz = __k; - for (; __first != __last; ++__first, (void)++__k) { - _Distance __r = _VSTD::uniform_int_distribution<_Distance>(0, __k)(__g); - if (__r < __sz) - __out[__r] = *__first; - } - return __out + _VSTD::min(__n, __k); -} - -template <class _PopulationIterator, class _SampleIterator, class _Distance, - class _UniformRandomNumberGenerator> -_LIBCPP_INLINE_VISIBILITY -_SampleIterator __sample(_PopulationIterator __first, - _PopulationIterator __last, _SampleIterator __out, - _Distance __n, - _UniformRandomNumberGenerator &&__g, - forward_iterator_tag) { - _Distance __unsampled_sz = _VSTD::distance(__first, __last); - for (__n = _VSTD::min(__n, __unsampled_sz); __n != 0; ++__first) { - _Distance __r = - _VSTD::uniform_int_distribution<_Distance>(0, --__unsampled_sz)(__g); - if (__r < __n) { - *__out++ = *__first; - --__n; - } - } - return __out; -} - -template <class _PopulationIterator, class _SampleIterator, class _Distance, - class _UniformRandomNumberGenerator> -_LIBCPP_INLINE_VISIBILITY -_SampleIterator sample(_PopulationIterator __first, - _PopulationIterator __last, _SampleIterator __out, - _Distance __n, _UniformRandomNumberGenerator &&__g) { - typedef typename iterator_traits<_PopulationIterator>::iterator_category - _PopCategory; - typedef typename iterator_traits<_PopulationIterator>::difference_type - _Difference; - static_assert(__is_forward_iterator<_PopulationIterator>::value || - __is_random_access_iterator<_SampleIterator>::value, - "SampleIterator must meet the requirements of RandomAccessIterator"); - typedef typename common_type<_Distance, _Difference>::type _CommonType; - _LIBCPP_ASSERT(__n >= 0, "N must be a positive number."); - return _VSTD_LFTS::__sample( - __first, __last, __out, _CommonType(__n), - _VSTD::forward<_UniformRandomNumberGenerator>(__g), - _PopCategory()); +inline _LIBCPP_INLINE_VISIBILITY +_SampleIterator sample(_PopulationIterator __first, _PopulationIterator __last, + _SampleIterator __out, _Distance __n, + _UniformRandomNumberGenerator &&__g) { + return _VSTD::__sample(__first, __last, __out, __n, __g); } _LIBCPP_END_NAMESPACE_LFTS 