1 files changed, 212 insertions, 0 deletions
diff --git a/contrib/llvm-project/libcxx/include/__random/discrete_distribution.h b/contrib/llvm-project/libcxx/include/__random/discrete_distribution.h
new file mode 100644
index 000000000000..bb72dd6cb507
--- /dev/null
+++ b/contrib/llvm-project/libcxx/include/__random/discrete_distribution.h
@@ -0,0 +1,212 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___RANDOM_DISCRETE_DISTRIBUTION_H
+#define _LIBCPP___RANDOM_DISCRETE_DISTRIBUTION_H
+
+#include <__algorithm/upper_bound.h>
+#include <__config>
+#include <__random/is_valid.h>
+#include <__random/uniform_real_distribution.h>
+#include <cstddef>
+#include <iosfwd>
+#include <numeric>
+#include <vector>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _IntType = int>
+class _LIBCPP_TEMPLATE_VIS discrete_distribution {
+  static_assert(__libcpp_random_is_valid_inttype<_IntType>::value, "IntType must be a supported integer type");
+
+public:
+  // types
+  typedef _IntType result_type;
+
+  class _LIBCPP_TEMPLATE_VIS param_type {
+    vector<double> __p_;
+
+  public:
+    typedef discrete_distribution distribution_type;
+
+    _LIBCPP_HIDE_FROM_ABI param_type() {}
+    template <class _InputIterator>
+    _LIBCPP_HIDE_FROM_ABI param_type(_InputIterator __f, _InputIterator __l) : __p_(__f, __l) {
+      __init();
+    }
+#ifndef _LIBCPP_CXX03_LANG
+    _LIBCPP_HIDE_FROM_ABI param_type(initializer_list<double> __wl) : __p_(__wl.begin(), __wl.end()) { __init(); }
+#endif // _LIBCPP_CXX03_LANG
+    template <class _UnaryOperation>
+    _LIBCPP_HIDE_FROM_ABI param_type(size_t __nw, double __xmin, double __xmax, _UnaryOperation __fw);
+
+    _LIBCPP_HIDE_FROM_ABI vector<double> probabilities() const;
+
+    friend _LIBCPP_HIDE_FROM_ABI bool operator==(const param_type& __x, const param_type& __y) {
+      return __x.__p_ == __y.__p_;
+    }
+    friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const param_type& __x, const param_type& __y) { return !(__x == __y); }
+
+  private:
+    _LIBCPP_HIDE_FROM_ABI void __init();
+
+    friend class discrete_distribution;
+
+    template <class _CharT, class _Traits, class _IT>
+    friend basic_ostream<_CharT, _Traits>&
+    operator<<(basic_ostream<_CharT, _Traits>& __os, const discrete_distribution<_IT>& __x);
+
+    template <class _CharT, class _Traits, class _IT>
+    friend basic_istream<_CharT, _Traits>&
+    operator>>(basic_istream<_CharT, _Traits>& __is, discrete_distribution<_IT>& __x);
+  };
+
+private:
+  param_type __p_;
+
+public:
+  // constructor and reset functions
+  _LIBCPP_HIDE_FROM_ABI discrete_distribution() {}
+  template <class _InputIterator>
+  _LIBCPP_HIDE_FROM_ABI discrete_distribution(_InputIterator __f, _InputIterator __l) : __p_(__f, __l) {}
+#ifndef _LIBCPP_CXX03_LANG
+  _LIBCPP_HIDE_FROM_ABI discrete_distribution(initializer_list<double> __wl) : __p_(__wl) {}
+#endif // _LIBCPP_CXX03_LANG
+  template <class _UnaryOperation>
+  _LIBCPP_HIDE_FROM_ABI discrete_distribution(size_t __nw, double __xmin, double __xmax, _UnaryOperation __fw)
+      : __p_(__nw, __xmin, __xmax, __fw) {}
+  _LIBCPP_HIDE_FROM_ABI explicit discrete_distribution(const param_type& __p) : __p_(__p) {}
+  _LIBCPP_HIDE_FROM_ABI void reset() {}
+
+  // generating functions
+  template <class _URNG>
+  _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g) {
+    return (*this)(__g, __p_);
+  }
+  template <class _URNG>
+  _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g, const param_type& __p);
+
+  // property functions
+  _LIBCPP_HIDE_FROM_ABI vector<double> probabilities() const { return __p_.probabilities(); }
+
+  _LIBCPP_HIDE_FROM_ABI param_type param() const { return __p_; }
+  _LIBCPP_HIDE_FROM_ABI void param(const param_type& __p) { __p_ = __p; }
+
+  _LIBCPP_HIDE_FROM_ABI result_type min() const { return 0; }
+  _LIBCPP_HIDE_FROM_ABI result_type max() const { return __p_.__p_.size(); }
+
+  friend _LIBCPP_HIDE_FROM_ABI bool operator==(const discrete_distribution& __x, const discrete_distribution& __y) {
+    return __x.__p_ == __y.__p_;
+  }
+  friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const discrete_distribution& __x, const discrete_distribution& __y) {
+    return !(__x == __y);
+  }
+
+  template <class _CharT, class _Traits, class _IT>
+  friend basic_ostream<_CharT, _Traits>&
+  operator<<(basic_ostream<_CharT, _Traits>& __os, const discrete_distribution<_IT>& __x);
+
+  template <class _CharT, class _Traits, class _IT>
+  friend basic_istream<_CharT, _Traits>&
+  operator>>(basic_istream<_CharT, _Traits>& __is, discrete_distribution<_IT>& __x);
+};
+
+template <class _IntType>
+template <class _UnaryOperation>
+discrete_distribution<_IntType>::param_type::param_type(
+    size_t __nw, double __xmin, double __xmax, _UnaryOperation __fw) {
+  if (__nw > 1) {
+    __p_.reserve(__nw - 1);
+    double __d  = (__xmax - __xmin) / __nw;
+    double __d2 = __d / 2;
+    for (size_t __k = 0; __k < __nw; ++__k)
+      __p_.push_back(__fw(__xmin + __k * __d + __d2));
+    __init();
+  }
+}
+
+template <class _IntType>
+void discrete_distribution<_IntType>::param_type::__init() {
+  if (!__p_.empty()) {
+    if (__p_.size() > 1) {
+      double __s = std::accumulate(__p_.begin(), __p_.end(), 0.0);
+      for (vector<double>::iterator __i = __p_.begin(), __e = __p_.end(); __i < __e; ++__i)
+        *__i /= __s;
+      vector<double> __t(__p_.size() - 1);
+      std::partial_sum(__p_.begin(), __p_.end() - 1, __t.begin());
+      swap(__p_, __t);
+    } else {
+      __p_.clear();
+      __p_.shrink_to_fit();
+    }
+  }
+}
+
+template <class _IntType>
+vector<double> discrete_distribution<_IntType>::param_type::probabilities() const {
+  size_t __n = __p_.size();
+  vector<double> __p(__n + 1);
+  std::adjacent_difference(__p_.begin(), __p_.end(), __p.begin());
+  if (__n > 0)
+    __p[__n] = 1 - __p_[__n - 1];
+  else
+    __p[0] = 1;
+  return __p;
+}
+
+template <class _IntType>
+template <class _URNG>
+_IntType discrete_distribution<_IntType>::operator()(_URNG& __g, const param_type& __p) {
+  static_assert(__libcpp_random_is_valid_urng<_URNG>::value, "");
+  uniform_real_distribution<double> __gen;
+  return static_cast<_IntType>(std::upper_bound(__p.__p_.begin(), __p.__p_.end(), __gen(__g)) - __p.__p_.begin());
+}
+
+template <class _CharT, class _Traits, class _IT>
+_LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os, const discrete_distribution<_IT>& __x) {
+  __save_flags<_CharT, _Traits> __lx(__os);
+  typedef basic_ostream<_CharT, _Traits> _OStream;
+  __os.flags(_OStream::dec | _OStream::left | _OStream::fixed | _OStream::scientific);
+  _CharT __sp = __os.widen(' ');
+  __os.fill(__sp);
+  size_t __n = __x.__p_.__p_.size();
+  __os << __n;
+  for (size_t __i = 0; __i < __n; ++__i)
+    __os << __sp << __x.__p_.__p_[__i];
+  return __os;
+}
+
+template <class _CharT, class _Traits, class _IT>
+_LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is, discrete_distribution<_IT>& __x) {
+  __save_flags<_CharT, _Traits> __lx(__is);
+  typedef basic_istream<_CharT, _Traits> _Istream;
+  __is.flags(_Istream::dec | _Istream::skipws);
+  size_t __n;
+  __is >> __n;
+  vector<double> __p(__n);
+  for (size_t __i = 0; __i < __n; ++__i)
+    __is >> __p[__i];
+  if (!__is.fail())
+    swap(__x.__p_.__p_, __p);
+  return __is;
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___RANDOM_DISCRETE_DISTRIBUTION_H