[rand.dist.samp.plinear]. This means we've got a fully tested and functional <random>! 489 tests over 48 sections are passing. :-) The only thing still on my plate in this area is to back-port some of this technology to random_shuffle/shuffle in <algorithm>. That will involve shuffling header bits around (<random> depepends on <algorithm>), but it won't entail that much development (compared to what has been required for <random>). git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@104575 91177308-0d34-0410-b5e6-96231b3b80d8 
diff --git a/include/random b/include/random index 1a680ff..adefa8b 100644 --- a/include/random +++ b/include/random 
@@ -1552,7 +1552,82 @@  };    template<class RealType = double> - class piecewise_linear_distribution; +class piecewise_linear_distribution +{ + // types + typedef RealType result_type; + + class param_type + { + public: + typedef piecewise_linear_distribution distribution_type; + + param_type(); + template<class InputIteratorB, class InputIteratorW> + param_type(InputIteratorB firstB, InputIteratorB lastB, + InputIteratorW firstW); + template<class UnaryOperation> + param_type(initializer_list<result_type> bl, UnaryOperation fw); + template<class UnaryOperation> + param_type(size_t nw, result_type xmin, result_type xmax, + UnaryOperation fw); + + vector<result_type> intervals() const; + vector<double> densities() const; + + friend bool operator==(const param_type& x, const param_type& y); + friend bool operator!=(const param_type& x, const param_type& y); + }; + + // constructor and reset functions + piecewise_linear_distribution(); + template<class InputIteratorB, class InputIteratorW> + piecewise_linear_distribution(InputIteratorB firstB, + InputIteratorB lastB, + InputIteratorW firstW); +  + template<class UnaryOperation> + piecewise_linear_distribution(initializer_list<result_type> bl, + UnaryOperation fw); + + template<class UnaryOperation> + piecewise_linear_distribution(size_t nw, result_type xmin, + result_type xmax, UnaryOperation fw); + + explicit piecewise_linear_distribution(const param_type& parm); + void reset(); + + // generating functions + template<class URNG> result_type operator()(URNG& g); + template<class URNG> result_type operator()(URNG& g, const param_type& parm); + + // property functions + vector<result_type> intervals() const; + vector<double> densities() const; + + param_type param() const; + void param(const param_type& parm); + + result_type min() const; + result_type max() const; + + friend bool operator==(const piecewise_linear_distribution& x, + const piecewise_linear_distribution& y); + friend bool operator!=(const piecewise_linear_distribution& x, + const piecewise_linear_distribution& y); + + template <class charT, class traits> + friend + basic_ostream<charT, traits>& + operator<<(basic_ostream<charT, traits>& os, + const piecewise_linear_distribution& x); +  + template <class charT, class traits> + friend + basic_istream<charT, traits>& + operator>>(basic_istream<charT, traits>& is, + piecewise_linear_distribution& x); +};    } // std  */ @@ -5772,7 +5847,8 @@  template<class _RealType>  piecewise_constant_distribution<_RealType>::param_type::param_type()  : __b_(2), - __densities_(1, 1.0) + __densities_(1, 1.0), + __areas_(1, 0.0)  {  __b_[1] = 1;  } @@ -5789,6 +5865,7 @@  __b_[0] = 0;  __b_[1] = 1;  __densities_.assign(1, 1.0); + __areas_.assign(1, 0.0);  }  else  { @@ -5811,6 +5888,7 @@  __b_[0] = 0;  __b_[1] = 1;  __densities_.assign(1, 1.0); + __areas_.assign(1, 0.0);  }  else  { @@ -5910,6 +5988,301 @@  return __is;  }   +// piecewise_linear_distribution + +template<class _RealType = double> +class piecewise_linear_distribution +{ +public: + // types + typedef _RealType result_type; + + class param_type + { + typedef typename common_type<double, result_type>::type __area_type; + vector<result_type> __b_; + vector<double> __densities_; + vector<__area_type> __areas_; + public: + typedef piecewise_linear_distribution distribution_type; + + param_type(); + template<class _InputIteratorB, class _InputIteratorW> + param_type(_InputIteratorB __fB, _InputIteratorB __lB, + _InputIteratorW __fW); + template<class _UnaryOperation> + param_type(initializer_list<result_type> __bl, _UnaryOperation __fw); + template<class _UnaryOperation> + param_type(size_t __nw, result_type __xmin, result_type __xmax, + _UnaryOperation __fw); + + vector<result_type> intervals() const {return __b_;} + vector<double> densities() const {return __densities_;} + + friend bool operator==(const param_type& __x, const param_type& __y) + {return __x.__densities_ == __y.__densities_ && __x.__b_ == __y.__b_;} + friend bool operator!=(const param_type& __x, const param_type& __y) + {return !(__x == __y);} + + private: + void __init(); + + friend class piecewise_linear_distribution; + + template <class _CharT, class _Traits, class _RT> + friend + basic_ostream<_CharT, _Traits>& + operator<<(basic_ostream<_CharT, _Traits>& __os, + const piecewise_linear_distribution<_RT>& __x); +  + template <class _CharT, class _Traits, class _RT> + friend + basic_istream<_CharT, _Traits>& + operator>>(basic_istream<_CharT, _Traits>& __is, + piecewise_linear_distribution<_RT>& __x); + }; + +private: + param_type __p_; + +public: + // constructor and reset functions + piecewise_linear_distribution() {} + template<class _InputIteratorB, class _InputIteratorW> + piecewise_linear_distribution(_InputIteratorB __fB, + _InputIteratorB __lB, + _InputIteratorW __fW) + : __p_(__fB, __lB, __fW) {} +  + template<class _UnaryOperation> + piecewise_linear_distribution(initializer_list<result_type> __bl, + _UnaryOperation __fw) + : __p_(__bl, __fw) {} + + template<class _UnaryOperation> + piecewise_linear_distribution(size_t __nw, result_type __xmin, + result_type __xmax, _UnaryOperation __fw) + : __p_(__nw, __xmin, __xmax, __fw) {} + + explicit piecewise_linear_distribution(const param_type& __p) + : __p_(__p) {} + + void reset() {} + + // generating functions + template<class _URNG> result_type operator()(_URNG& __g) + {return (*this)(__g, __p_);} + template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p); + + // property functions + vector<result_type> intervals() const {return __p_.intervals();} + vector<double> densities() const {return __p_.densities();} + + param_type param() const {return __p_;} + void param(const param_type& __p) {__p_ = __p;} + + result_type min() const {return __p_.__b_.front();} + result_type max() const {return __p_.__b_.back();} + + friend bool operator==(const piecewise_linear_distribution& __x, + const piecewise_linear_distribution& __y) + {return __x.__p_ == __y.__p_;} + friend bool operator!=(const piecewise_linear_distribution& __x, + const piecewise_linear_distribution& __y) + {return !(__x == __y);} + + template <class _CharT, class _Traits, class _RT> + friend + basic_ostream<_CharT, _Traits>& + operator<<(basic_ostream<_CharT, _Traits>& __os, + const piecewise_linear_distribution<_RT>& __x); +  + template <class _CharT, class _Traits, class _RT> + friend + basic_istream<_CharT, _Traits>& + operator>>(basic_istream<_CharT, _Traits>& __is, + piecewise_linear_distribution<_RT>& __x); +}; + +template<class _RealType> +void +piecewise_linear_distribution<_RealType>::param_type::__init() +{ + __areas_.assign(__densities_.size() - 1, __area_type()); + __area_type _S = 0; + for (size_t __i = 0; __i < __areas_.size(); ++__i) + { + __areas_[__i] = (__densities_[__i+1] + __densities_[__i]) * + (__b_[__i+1] - __b_[__i]) * .5; + _S += __areas_[__i]; + } + for (size_t __i = __areas_.size(); __i > 1;) + { + --__i; + __areas_[__i] = __areas_[__i-1] / _S; + } + __areas_[0] = 0; + for (size_t __i = 1; __i < __areas_.size(); ++__i) + __areas_[__i] += __areas_[__i-1]; + for (size_t __i = 0; __i < __densities_.size(); ++__i) + __densities_[__i] /= _S; +} + +template<class _RealType> +piecewise_linear_distribution<_RealType>::param_type::param_type() + : __b_(2), + __densities_(2, 1.0), + __areas_(1, 0.0) +{ + __b_[1] = 1; +} + +template<class _RealType> +template<class _InputIteratorB, class _InputIteratorW> +piecewise_linear_distribution<_RealType>::param_type::param_type( + _InputIteratorB __fB, _InputIteratorB __lB, _InputIteratorW __fW) + : __b_(__fB, __lB) +{ + if (__b_.size() < 2) + { + __b_.resize(2); + __b_[0] = 0; + __b_[1] = 1; + __densities_.assign(2, 1.0); + __areas_.assign(1, 0.0); + } + else + { + __densities_.reserve(__b_.size()); + for (size_t __i = 0; __i < __b_.size(); ++__i, ++__fW) + __densities_.push_back(*__fW); + __init(); + } +} + +template<class _RealType> +template<class _UnaryOperation> +piecewise_linear_distribution<_RealType>::param_type::param_type( + initializer_list<result_type> __bl, _UnaryOperation __fw) + : __b_(__bl.begin(), __bl.end()) +{ + if (__b_.size() < 2) + { + __b_.resize(2); + __b_[0] = 0; + __b_[1] = 1; + __densities_.assign(2, 1.0); + __areas_.assign(1, 0.0); + } + else + { + __densities_.reserve(__b_.size()); + for (size_t __i = 0; __i < __b_.size(); ++__i) + __densities_.push_back(__fw(__b_[__i])); + __init(); + } +} + +template<class _RealType> +template<class _UnaryOperation> +piecewise_linear_distribution<_RealType>::param_type::param_type( + size_t __nw, result_type __xmin, result_type __xmax, _UnaryOperation __fw) + : __b_(__nw == 0 ? 2 : __nw + 1) +{ + size_t __n = __b_.size() - 1; + result_type __d = (__xmax - __xmin) / __n; + __densities_.reserve(__b_.size()); + for (size_t __i = 0; __i < __n; ++__i) + { + __b_[__i] = __xmin + __i * __d; + __densities_.push_back(__fw(__b_[__i])); + } + __b_[__n] = __xmax; + __densities_.push_back(__fw(__b_[__n])); + __init(); +} + +template<class _RealType> +template<class _URNG> +_RealType +piecewise_linear_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p) +{ + typedef uniform_real_distribution<result_type> _Gen; + result_type __u = _Gen()(__g); + ptrdiff_t __k = _STD::upper_bound(__p.__areas_.begin(), __p.__areas_.end(), + static_cast<double>(__u)) - __p.__areas_.begin() - 1; + __u -= __p.__areas_[__k]; + const double __dk = __p.__densities_[__k]; + const double __dk1 = __p.__densities_[__k+1]; + const double __deltad = __dk1 - __dk; + const result_type __bk = __p.__b_[__k]; + if (__deltad == 0) + return static_cast<result_type>(__u / __dk + __bk); + const result_type __bk1 = __p.__b_[__k+1]; + const result_type __deltab = __bk1 - __bk; + return static_cast<result_type>((__bk * __dk1 - __bk1 * __dk +  + _STD::sqrt(__deltab * (__deltab * __dk * __dk + 2 * __deltad * __u))) / + __deltad); +} + +template <class _CharT, class _Traits, class _RT> +basic_ostream<_CharT, _Traits>& +operator<<(basic_ostream<_CharT, _Traits>& __os, + const piecewise_linear_distribution<_RT>& __x) +{ + __save_flags<_CharT, _Traits> _(__os); + __os.flags(ios_base::dec | ios_base::left | ios_base::fixed | + ios_base::scientific); + _CharT __sp = __os.widen(' '); + __os.fill(__sp); + size_t __n = __x.__p_.__b_.size(); + __os << __n; + for (size_t __i = 0; __i < __n; ++__i) + __os << __sp << __x.__p_.__b_[__i]; + __n = __x.__p_.__densities_.size(); + __os << __sp << __n; + for (size_t __i = 0; __i < __n; ++__i) + __os << __sp << __x.__p_.__densities_[__i]; + __n = __x.__p_.__areas_.size(); + __os << __sp << __n; + for (size_t __i = 0; __i < __n; ++__i) + __os << __sp << __x.__p_.__areas_[__i]; + return __os; +} + +template <class _CharT, class _Traits, class _RT> +basic_istream<_CharT, _Traits>& +operator>>(basic_istream<_CharT, _Traits>& __is, + piecewise_linear_distribution<_RT>& __x) +{ + typedef piecewise_linear_distribution<_RT> _Eng; + typedef typename _Eng::result_type result_type; + typedef typename _Eng::param_type param_type; + typedef typename param_type::__area_type __area_type; + __save_flags<_CharT, _Traits> _(__is); + __is.flags(ios_base::dec | ios_base::skipws); + size_t __n; + __is >> __n; + vector<result_type> __b(__n); + for (size_t __i = 0; __i < __n; ++__i) + __is >> __b[__i]; + __is >> __n; + vector<double> __densities(__n); + for (size_t __i = 0; __i < __n; ++__i) + __is >> __densities[__i]; + __is >> __n; + vector<__area_type> __areas(__n); + for (size_t __i = 0; __i < __n; ++__i) + __is >> __areas[__i]; + if (!__is.fail()) + { + swap(__x.__p_.__b_, __b); + swap(__x.__p_.__densities_, __densities); + swap(__x.__p_.__areas_, __areas); + } + return __is; +} +  _LIBCPP_END_NAMESPACE_STD    #endif // _LIBCPP_RANDOM