[rand.dist.samp.discrete]

llvm-svn: 104103
2010-05-19 01:53:57 +00:00 · 2010-05-19 01:53:57 +00:00 · fb0e5ec825
parent 2c452fcd14
commit fb0e5ec825
25 changed files with 1602 additions and 3 deletions
--- a/libcxx/include/random
+++ b/libcxx/include/random
@ -1410,7 +1410,71 @@ public:
 };

 template<class IntType = int>
-    class discrete_distribution;
+class discrete_distribution
+{
+public:
+    // types
+    typedef IntType result_type;
+
+    class param_type
+    {
+    public:
+        typedef discrete_distribution distribution_type;
+
+        param_type();
+        template<class InputIterator>
+            param_type(InputIterator firstW, InputIterator lastW);
+        param_type(initializer_list<double> wl);
+        template<class UnaryOperation>
+            param_type(size_t nw, double xmin, double xmax, UnaryOperation fw);
+
+        vector<double> probabilities() 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
+    discrete_distribution();
+    template<class InputIterator>
+        discrete_distribution(InputIterator firstW, InputIterator lastW);
+    discrete_distribution(initializer_list<double> wl);
+    template<class UnaryOperation>
+        discrete_distribution(size_t nw, double xmin, double xmax,
+                              UnaryOperation fw);
+    explicit discrete_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<double> probabilities() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const discrete_distribution& x,
+                           const discrete_distribution& y);
+    friend bool operator!=(const discrete_distribution& x,
+                           const discrete_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const discrete_distribution& x);
+    
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               discrete_distribution& x);
+};

 template<class RealType = double>
    class piecewise_constant_distribution;
@ -1428,6 +1492,7 @@ template<class RealType = double>
 #include <cstdint>
 #include <limits>
 #include <algorithm>
+#include <numeric>
 #include <vector>
 #include <string>
 #include <istream>
@ -4075,7 +4140,7 @@ public:
    result_type s() const {return __p_.s();}

    param_type param() const {return __p_;}
-    void param(const param_type& __p) {return __p_ = __p;}
+    void param(const param_type& __p) {__p_ = __p;}

    result_type min() const {return 0;}
    result_type max() const {return numeric_limits<result_type>::infinity();}
@ -5176,6 +5241,8 @@ operator>>(basic_istream<_CharT, _Traits>& __is,
    return __is;
 }

+// student_t_distribution
+
 template<class _RealType = double>
 class student_t_distribution
 {
@ -5220,7 +5287,7 @@ public:
    result_type n() const {return __p_.n();}

    param_type param() const {return __p_;}
-    void param(const param_type& __p) {return __p_ = __p;}
+    void param(const param_type& __p) {__p_ = __p;}

    result_type min() const {return -numeric_limits<result_type>::infinity();}
    result_type max() const {return numeric_limits<result_type>::infinity();}
@ -5270,6 +5337,212 @@ operator>>(basic_istream<_CharT, _Traits>& __is,
    return __is;
 }

+// discrete_distribution
+
+template<class _IntType = int>
+class discrete_distribution
+{
+public:
+    // types
+    typedef _IntType result_type;
+
+    class param_type
+    {
+        vector<double> __p_;
+    public:
+        typedef discrete_distribution distribution_type;
+
+        param_type() {}
+        template<class _InputIterator>
+            param_type(_InputIterator __f, _InputIterator __l)
+            : __p_(__f, __l) {__init();}
+        param_type(initializer_list<double> __wl)
+            : __p_(__wl.begin(), __wl.end()) {__init();}
+        template<class _UnaryOperation>
+            param_type(size_t __nw, double __xmin, double __xmax,
+                       _UnaryOperation __fw);
+
+        vector<double> probabilities() const;
+
+        friend bool operator==(const param_type& __x, const param_type& __y)
+            {return __x.__p_ == __y.__p_;}
+        friend bool operator!=(const param_type& __x, const param_type& __y)
+            {return !(__x == __y);}
+
+    private:
+        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
+    discrete_distribution() {}
+    template<class _InputIterator>
+        discrete_distribution(_InputIterator __f, _InputIterator __l)
+            : __p_(__f, __l) {}
+    discrete_distribution(initializer_list<double> __wl)
+        : __p_(__wl) {}
+    template<class _UnaryOperation>
+        discrete_distribution(size_t __nw, double __xmin, double __xmax,
+                              _UnaryOperation __fw)
+        : __p_(__nw, __xmin, __xmax, __fw) {}
+    explicit discrete_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<double> probabilities() const {return __p_.probabilities();}
+
+    param_type param() const {return __p_;}
+    void param(const param_type& __p) {__p_ = __p;}
+
+    result_type min() const {return 0;}
+    result_type max() const {return __p_.__p_.size();}
+
+    friend bool operator==(const discrete_distribution& __x,
+                           const discrete_distribution& __y)
+        {return __x.__p_ == __y.__p_;}
+    friend 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 (_STD::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();
+    _STD::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)
+{
+    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>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os,
+           const discrete_distribution<_IT>& __x)
+{
+    __save_flags<_CharT, _Traits> _(__os);
+    __os.flags(ios_base::dec | ios_base::left);
+    _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>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is,
+           discrete_distribution<_IT>& __x)
+{
+    typedef discrete_distribution<_IT> _Eng;
+    typedef typename _Eng::result_type result_type;
+    typedef typename _Eng::param_type param_type;
+    __save_flags<_CharT, _Traits> _(__is);
+    __is.flags(ios_base::dec | ios_base::skipws);
+    size_t __n;
+    __is >> __n;
+    std::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

 #endif  // _LIBCPP_RANDOM
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/assign.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/assign.pass.cpp
@ -0,0 +1,35 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// discrete_distribution& operator=(const discrete_distribution&);
+
+#include <random>
+#include <cassert>
+
+void
+test1()
+{
+    typedef std::discrete_distribution<> D;
+    double p[] = {2, 4, 1, 8};
+    D d1(p, p+4);
+    D d2;
+    assert(d1 != d2);
+    d2 = d1;
+    assert(d1 == d2);
+}
+
+int main()
+{
+    test1();
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/copy.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/copy.pass.cpp
@ -0,0 +1,33 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// discrete_distribution(const discrete_distribution&);
+
+#include <random>
+#include <cassert>
+
+void
+test1()
+{
+    typedef std::discrete_distribution<> D;
+    double p[] = {2, 4, 1, 8};
+    D d1(p, p+4);
+    D d2 = d1;
+    assert(d1 == d2);
+}
+
+int main()
+{
+    test1();
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/ctor_default.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/ctor_default.pass.cpp
@ -0,0 +1,29 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// discrete_distribution(initializer_list<double> wl);
+
+#include <random>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        D d;
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 1);
+        assert(p[0] == 1);
+    }
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/ctor_func.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/ctor_func.pass.cpp
@ -0,0 +1,60 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// template<class UnaryOperation>
+//     discrete_distribution(size_t nw, double xmin, double xmax,
+//                           UnaryOperation fw);
+
+#include <random>
+#include <cassert>
+
+double fw(double x)
+{
+    return x+1;
+}
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        D d(0, 0, 1, fw);
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 1);
+        assert(p[0] == 1);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        D d(1, 0, 1, fw);
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 1);
+        assert(p[0] == 1);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        D d(2, 0.5, 1.5, fw);
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 2);
+        assert(p[0] == .4375);
+        assert(p[1] == .5625);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        D d(4, 0, 2, fw);
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 4);
+        assert(p[0] == .15625);
+        assert(p[1] == .21875);
+        assert(p[2] == .28125);
+    }
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/ctor_init.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/ctor_init.pass.cpp
@ -0,0 +1,81 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// discrete_distribution(initializer_list<double> wl);
+
+#include <random>
+#include <cassert>
+
+int main()
+{
+#ifdef _LIBCPP_MOVE
+    {
+        typedef std::discrete_distribution<> D;
+        D d = {};
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 1);
+        assert(p[0] == 1);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        D d = {10};
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 1);
+        assert(p[0] == 1);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        D d = {10, 30};
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 2);
+        assert(p[0] == 0.25);
+        assert(p[1] == 0.75);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        D d = {30, 10};
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 2);
+        assert(p[0] == 0.75);
+        assert(p[1] == 0.25);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        D d = {30, 0, 10};
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 3);
+        assert(p[0] == 0.75);
+        assert(p[1] == 0);
+        assert(p[2] == 0.25);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        D d = {0, 30, 10};
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 3);
+        assert(p[0] == 0);
+        assert(p[1] == 0.75);
+        assert(p[2] == 0.25);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        D d = {0, 0, 10};
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 3);
+        assert(p[0] == 0);
+        assert(p[1] == 0);
+        assert(p[2] == 1);
+    }
+#endif
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/ctor_iterator.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/ctor_iterator.pass.cpp
@ -0,0 +1,87 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// template<class InputIterator>
+//     discrete_distribution(InputIterator firstW, InputIterator lastW);
+
+#include <random>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        double p0[] = {1};
+        D d(p0, p0);
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 1);
+        assert(p[0] == 1);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        double p0[] = {10};
+        D d(p0, p0+1);
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 1);
+        assert(p[0] == 1);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        double p0[] = {10, 30};
+        D d(p0, p0+2);
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 2);
+        assert(p[0] == 0.25);
+        assert(p[1] == 0.75);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        double p0[] = {30, 10};
+        D d(p0, p0+2);
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 2);
+        assert(p[0] == 0.75);
+        assert(p[1] == 0.25);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        double p0[] = {30, 0, 10};
+        D d(p0, p0+3);
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 3);
+        assert(p[0] == 0.75);
+        assert(p[1] == 0);
+        assert(p[2] == 0.25);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        double p0[] = {0, 30, 10};
+        D d(p0, p0+3);
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 3);
+        assert(p[0] == 0);
+        assert(p[1] == 0.75);
+        assert(p[2] == 0.25);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        double p0[] = {0, 0, 10};
+        D d(p0, p0+3);
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 3);
+        assert(p[0] == 0);
+        assert(p[1] == 0);
+        assert(p[2] == 1);
+    }
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/ctor_param.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/ctor_param.pass.cpp
@ -0,0 +1,33 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// explicit discrete_distribution(const param_type& parm);
+
+#include <random>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        double p0[] = {10, 30};
+        P pa(p0, p0+2);
+        D d(pa);
+        std::vector<double> p = d.probabilities();
+        assert(p.size() == 2);
+        assert(p[0] == 0.25);
+        assert(p[1] == 0.75);
+    }
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/eq.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/eq.pass.cpp
@ -0,0 +1,45 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// bool operator=(const discrete_distribution& x,
+//                const discrete_distribution& y);
+// bool operator!(const discrete_distribution& x,
+//                const discrete_distribution& y);
+
+#include <random>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        D d1;
+        D d2;
+        assert(d1 == d2);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        double p0[] = {1};
+        D d1(p0, p0+1);
+        D d2;
+        assert(d1 == d2);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        double p0[] = {10, 30};
+        D d1(p0, p0+2);
+        D d2;
+        assert(d1 != d2);
+    }
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/eval.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/eval.pass.cpp
@ -0,0 +1,277 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// template<class _URNG> result_type operator()(_URNG& g);
+
+#include <random>
+#include <vector>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        typedef std::minstd_rand G;
+        G g;
+        D d;
+        const int N = 100;
+        std::vector<D::result_type> u(d.max()+1);
+        for (int i = 0; i < N; ++i)
+        {
+            D::result_type v = d(g);
+            assert(d.min() <= v && v <= d.max());
+            u[v]++;
+        }
+        std::vector<double> prob = d.probabilities();
+        for (int i = 0; i <= d.max(); ++i)
+            assert((double)u[i]/N == prob[i]);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef std::minstd_rand G;
+        G g;
+        double p0[] = {.3};
+        D d(p0, p0+1);
+        const int N = 100;
+        std::vector<D::result_type> u(d.max()+1);
+        for (int i = 0; i < N; ++i)
+        {
+            D::result_type v = d(g);
+            assert(d.min() <= v && v <= d.max());
+            u[v]++;
+        }
+        std::vector<double> prob = d.probabilities();
+        for (int i = 0; i <= d.max(); ++i)
+            assert((double)u[i]/N == prob[i]);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef std::minstd_rand G;
+        G g;
+        double p0[] = {.75, .25};
+        D d(p0, p0+2);
+        const int N = 1000000;
+        std::vector<D::result_type> u(d.max()+1);
+        for (int i = 0; i < N; ++i)
+        {
+            D::result_type v = d(g);
+            assert(d.min() <= v && v <= d.max());
+            u[v]++;
+        }
+        std::vector<double> prob = d.probabilities();
+        for (int i = 0; i <= d.max(); ++i)
+            assert(std::abs((double)u[i]/N - prob[i]) / prob[i] < 0.001);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef std::minstd_rand G;
+        G g;
+        double p0[] = {0, 1};
+        D d(p0, p0+2);
+        const int N = 1000000;
+        std::vector<D::result_type> u(d.max()+1);
+        for (int i = 0; i < N; ++i)
+        {
+            D::result_type v = d(g);
+            assert(d.min() <= v && v <= d.max());
+            u[v]++;
+        }
+        std::vector<double> prob = d.probabilities();
+        assert((double)u[0]/N == prob[0]);
+        assert((double)u[1]/N == prob[1]);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef std::minstd_rand G;
+        G g;
+        double p0[] = {1, 0};
+        D d(p0, p0+2);
+        const int N = 1000000;
+        std::vector<D::result_type> u(d.max()+1);
+        for (int i = 0; i < N; ++i)
+        {
+            D::result_type v = d(g);
+            assert(d.min() <= v && v <= d.max());
+            u[v]++;
+        }
+        std::vector<double> prob = d.probabilities();
+        assert((double)u[0]/N == prob[0]);
+        assert((double)u[1]/N == prob[1]);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef std::minstd_rand G;
+        G g;
+        double p0[] = {.3, .1, .6};
+        D d(p0, p0+3);
+        const int N = 10000000;
+        std::vector<D::result_type> u(d.max()+1);
+        for (int i = 0; i < N; ++i)
+        {
+            D::result_type v = d(g);
+            assert(d.min() <= v && v <= d.max());
+            u[v]++;
+        }
+        std::vector<double> prob = d.probabilities();
+        for (int i = 0; i <= d.max(); ++i)
+            assert(std::abs((double)u[i]/N - prob[i]) / prob[i] < 0.001);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef std::minstd_rand G;
+        G g;
+        double p0[] = {0, 25, 75};
+        D d(p0, p0+3);
+        const int N = 1000000;
+        std::vector<D::result_type> u(d.max()+1);
+        for (int i = 0; i < N; ++i)
+        {
+            D::result_type v = d(g);
+            assert(d.min() <= v && v <= d.max());
+            u[v]++;
+        }
+        std::vector<double> prob = d.probabilities();
+        for (int i = 0; i <= d.max(); ++i)
+            if (prob[i] != 0)
+                assert(std::abs((double)u[i]/N - prob[i]) / prob[i] < 0.001);
+            else
+                assert(u[i] == 0);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef std::minstd_rand G;
+        G g;
+        double p0[] = {25, 0, 75};
+        D d(p0, p0+3);
+        const int N = 1000000;
+        std::vector<D::result_type> u(d.max()+1);
+        for (int i = 0; i < N; ++i)
+        {
+            D::result_type v = d(g);
+            assert(d.min() <= v && v <= d.max());
+            u[v]++;
+        }
+        std::vector<double> prob = d.probabilities();
+        for (int i = 0; i <= d.max(); ++i)
+            if (prob[i] != 0)
+                assert(std::abs((double)u[i]/N - prob[i]) / prob[i] < 0.001);
+            else
+                assert(u[i] == 0);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef std::minstd_rand G;
+        G g;
+        double p0[] = {25, 75, 0};
+        D d(p0, p0+3);
+        const int N = 1000000;
+        std::vector<D::result_type> u(d.max()+1);
+        for (int i = 0; i < N; ++i)
+        {
+            D::result_type v = d(g);
+            assert(d.min() <= v && v <= d.max());
+            u[v]++;
+        }
+        std::vector<double> prob = d.probabilities();
+        for (int i = 0; i <= d.max(); ++i)
+            if (prob[i] != 0)
+                assert(std::abs((double)u[i]/N - prob[i]) / prob[i] < 0.001);
+            else
+                assert(u[i] == 0);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef std::minstd_rand G;
+        G g;
+        double p0[] = {0, 0, 1};
+        D d(p0, p0+3);
+        const int N = 100;
+        std::vector<D::result_type> u(d.max()+1);
+        for (int i = 0; i < N; ++i)
+        {
+            D::result_type v = d(g);
+            assert(d.min() <= v && v <= d.max());
+            u[v]++;
+        }
+        std::vector<double> prob = d.probabilities();
+        for (int i = 0; i <= d.max(); ++i)
+            if (prob[i] != 0)
+                assert(std::abs((double)u[i]/N - prob[i]) / prob[i] < 0.001);
+            else
+                assert(u[i] == 0);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef std::minstd_rand G;
+        G g;
+        double p0[] = {0, 1, 0};
+        D d(p0, p0+3);
+        const int N = 100;
+        std::vector<D::result_type> u(d.max()+1);
+        for (int i = 0; i < N; ++i)
+        {
+            D::result_type v = d(g);
+            assert(d.min() <= v && v <= d.max());
+            u[v]++;
+        }
+        std::vector<double> prob = d.probabilities();
+        for (int i = 0; i <= d.max(); ++i)
+            if (prob[i] != 0)
+                assert(std::abs((double)u[i]/N - prob[i]) / prob[i] < 0.001);
+            else
+                assert(u[i] == 0);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef std::minstd_rand G;
+        G g;
+        double p0[] = {1, 0, 0};
+        D d(p0, p0+3);
+        const int N = 100;
+        std::vector<D::result_type> u(d.max()+1);
+        for (int i = 0; i < N; ++i)
+        {
+            D::result_type v = d(g);
+            assert(d.min() <= v && v <= d.max());
+            u[v]++;
+        }
+        std::vector<double> prob = d.probabilities();
+        for (int i = 0; i <= d.max(); ++i)
+            if (prob[i] != 0)
+                assert(std::abs((double)u[i]/N - prob[i]) / prob[i] < 0.001);
+            else
+                assert(u[i] == 0);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef std::minstd_rand G;
+        G g;
+        double p0[] = {33, 0, 0, 67};
+        D d(p0, p0+3);
+        const int N = 1000000;
+        std::vector<D::result_type> u(d.max()+1);
+        for (int i = 0; i < N; ++i)
+        {
+            D::result_type v = d(g);
+            assert(d.min() <= v && v <= d.max());
+            u[v]++;
+        }
+        std::vector<double> prob = d.probabilities();
+        for (int i = 0; i <= d.max(); ++i)
+            if (prob[i] != 0)
+                assert(std::abs((double)u[i]/N - prob[i]) / prob[i] < 0.001);
+            else
+                assert(u[i] == 0);
+    }
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/eval_param.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/eval_param.pass.cpp
@ -0,0 +1,43 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// template<class _URNG> result_type operator()(_URNG& g, const param_type& parm);
+
+#include <random>
+#include <vector>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        typedef std::minstd_rand G;
+        G g;
+        D d;
+        double p0[] = {.3, .1, .6};
+        P p(p0, p0+3);
+        const int N = 10000000;
+        std::vector<D::result_type> u(3);
+        for (int i = 0; i < N; ++i)
+        {
+            D::result_type v = d(g, p);
+            assert(0 <= v && v <= 2);
+            u[v]++;
+        }
+        std::vector<double> prob = p.probabilities();
+        for (int i = 0; i <= 2; ++i)
+            assert(std::abs((double)u[i]/N - prob[i]) / prob[i] < 0.001);
+    }
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/get_param.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/get_param.pass.cpp
@ -0,0 +1,30 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// param_type param() const;
+
+#include <random>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        double p0[] = {.3, .1, .6};
+        P p(p0, p0+3);
+        D d(p);
+        assert(d.param() == p);
+    }
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/io.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/io.pass.cpp
@ -0,0 +1,42 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// template <class charT, class traits>
+// basic_ostream<charT, traits>&
+// operator<<(basic_ostream<charT, traits>& os,
+//            const discrete_distribution& x);
+// 
+// template <class charT, class traits>
+// basic_istream<charT, traits>&
+// operator>>(basic_istream<charT, traits>& is,
+//            discrete_distribution& x);
+
+#include <random>
+#include <sstream>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        double p0[] = {.3, .1, .6};
+        D d1(p0, p0+3);
+        std::ostringstream os;
+        os << d1;
+        std::istringstream is(os.str());
+        D d2;
+        is >> d2;
+        assert(d1 == d2);
+    }
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/max.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/max.pass.cpp
@ -0,0 +1,34 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// result_type max() const;
+
+#include <random>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        double p0[] = {.3, .1, .6};
+        D d(p0, p0+3);
+        assert(d.max() == 2);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        double p0[] = {.3, .1, .6, .2};
+        D d(p0, p0+4);
+        assert(d.max() == 3);
+    }
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/min.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/min.pass.cpp
@ -0,0 +1,28 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// result_type min() const;
+
+#include <random>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        double p0[] = {.3, .1, .6};
+        D d(p0, p0+3);
+        assert(d.min() == 0);
+    }
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/param_assign.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/param_assign.pass.cpp
@ -0,0 +1,32 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+// {
+//     class param_type;
+
+#include <random>
+#include <limits>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type param_type;
+        double d0[] = {.3, .1, .6};
+        param_type p0(d0, d0+3);
+        param_type p;
+        p = p0;
+        assert(p == p0);
+    }
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/param_copy.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/param_copy.pass.cpp
@ -0,0 +1,31 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+// {
+//     class param_type;
+
+#include <random>
+#include <limits>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type param_type;
+        double d0[] = {.3, .1, .6};
+        param_type p0(d0, d0+3);
+        param_type p = p0;
+        assert(p == p0);
+    }
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/param_ctor_default.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/param_ctor_default.pass.cpp
@ -0,0 +1,30 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// param_type(initializer_list<double> wl);
+
+#include <random>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        P pa;
+        std::vector<double> p = pa.probabilities();
+        assert(p.size() == 1);
+        assert(p[0] == 1);
+    }
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/param_ctor_func.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/param_ctor_func.pass.cpp
@ -0,0 +1,64 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// template<class UnaryOperation>
+//     param_type(size_t nw, double xmin, double xmax,
+//                           UnaryOperation fw);
+
+#include <random>
+#include <cassert>
+
+double fw(double x)
+{
+    return x+1;
+}
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        P pa(0, 0, 1, fw);
+        std::vector<double> p = pa.probabilities();
+        assert(p.size() == 1);
+        assert(p[0] == 1);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        P pa(1, 0, 1, fw);
+        std::vector<double> p = pa.probabilities();
+        assert(p.size() == 1);
+        assert(p[0] == 1);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        P pa(2, 0.5, 1.5, fw);
+        std::vector<double> p = pa.probabilities();
+        assert(p.size() == 2);
+        assert(p[0] == .4375);
+        assert(p[1] == .5625);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        P pa(4, 0, 2, fw);
+        std::vector<double> p = pa.probabilities();
+        assert(p.size() == 4);
+        assert(p[0] == .15625);
+        assert(p[1] == .21875);
+        assert(p[2] == .28125);
+    }
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/param_ctor_init.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/param_ctor_init.pass.cpp
@ -0,0 +1,88 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// param_type(initializer_list<double> wl);
+
+#include <random>
+#include <cassert>
+
+int main()
+{
+#ifdef _LIBCPP_MOVE
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        P pa = {};
+        std::vector<double> p = pa.probabilities();
+        assert(p.size() == 1);
+        assert(p[0] == 1);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        P pa = {10};
+        std::vector<double> p = pa.probabilities();
+        assert(p.size() == 1);
+        assert(p[0] == 1);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        P pa = {10, 30};
+        std::vector<double> p = pa.probabilities();
+        assert(p.size() == 2);
+        assert(p[0] == 0.25);
+        assert(p[1] == 0.75);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        P pa = {30, 10};
+        std::vector<double> p = pa.probabilities();
+        assert(p.size() == 2);
+        assert(p[0] == 0.75);
+        assert(p[1] == 0.25);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        P pa = {30, 0, 10};
+        std::vector<double> p = pa.probabilities();
+        assert(p.size() == 3);
+        assert(p[0] == 0.75);
+        assert(p[1] == 0);
+        assert(p[2] == 0.25);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        P pa = {0, 30, 10};
+        std::vector<double> p = pa.probabilities();
+        assert(p.size() == 3);
+        assert(p[0] == 0);
+        assert(p[1] == 0.75);
+        assert(p[2] == 0.25);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        P pa = {0, 0, 10};
+        std::vector<double> p = pa.probabilities();
+        assert(p.size() == 3);
+        assert(p[0] == 0);
+        assert(p[1] == 0);
+        assert(p[2] == 1);
+    }
+#endif
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/param_ctor_iterator.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/param_ctor_iterator.pass.cpp
@ -0,0 +1,94 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// template<class InputIterator>
+//     param_type(InputIterator firstW, InputIterator lastW);
+
+#include <random>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        double p0[] = {1};
+        P pa(p0, p0);
+        std::vector<double> p = pa.probabilities();
+        assert(p.size() == 1);
+        assert(p[0] == 1);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        double p0[] = {10};
+        P pa(p0, p0+1);
+        std::vector<double> p = pa.probabilities();
+        assert(p.size() == 1);
+        assert(p[0] == 1);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        double p0[] = {10, 30};
+        P pa(p0, p0+2);
+        std::vector<double> p = pa.probabilities();
+        assert(p.size() == 2);
+        assert(p[0] == 0.25);
+        assert(p[1] == 0.75);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        double p0[] = {30, 10};
+        P pa(p0, p0+2);
+        std::vector<double> p = pa.probabilities();
+        assert(p.size() == 2);
+        assert(p[0] == 0.75);
+        assert(p[1] == 0.25);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        double p0[] = {30, 0, 10};
+        P pa(p0, p0+3);
+        std::vector<double> p = pa.probabilities();
+        assert(p.size() == 3);
+        assert(p[0] == 0.75);
+        assert(p[1] == 0);
+        assert(p[2] == 0.25);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        double p0[] = {0, 30, 10};
+        P pa(p0, p0+3);
+        std::vector<double> p = pa.probabilities();
+        assert(p.size() == 3);
+        assert(p[0] == 0);
+        assert(p[1] == 0.75);
+        assert(p[2] == 0.25);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        double p0[] = {0, 0, 10};
+        P pa(p0, p0+3);
+        std::vector<double> p = pa.probabilities();
+        assert(p.size() == 3);
+        assert(p[0] == 0);
+        assert(p[1] == 0);
+        assert(p[2] == 1);
+    }
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/param_eq.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/param_eq.pass.cpp
@ -0,0 +1,39 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+// {
+//     class param_type;
+
+#include <random>
+#include <limits>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type param_type;
+        double p0[] = {30, 10};
+        param_type p1(p0, p0+2);
+        param_type p2(p0, p0+2);
+        assert(p1 == p2);
+    }
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type param_type;
+        double p0[] = {30, 10};
+        param_type p1(p0, p0+2);
+        param_type p2;
+        assert(p1 != p2);
+    }
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/param_types.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/param_types.pass.cpp
@ -0,0 +1,28 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+// {
+//     class param_type;
+
+#include <random>
+#include <type_traits>
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type param_type;
+        typedef param_type::distribution_type distribution_type;
+        static_assert((std::is_same<D, distribution_type>::value), "");
+    }
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/set_param.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/set_param.pass.cpp
@ -0,0 +1,31 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+
+// void param(const param_type& parm);
+
+#include <random>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::param_type P;
+        double d0[] = {.3, .1, .6};
+        P p(d0, d0+3);
+        D d;
+        d.param(p);
+        assert(d.param() == p);
+    }
+}
--- a/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/types.pass.cpp
+++ b/libcxx/test/numerics/rand/rand.dis/rand.dist.samp/rand.dist.samp.discrete/types.pass.cpp
@ -0,0 +1,32 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class IntType = int>
+// class discrete_distribution
+// {
+//     typedef bool result_type;
+
+#include <random>
+#include <type_traits>
+
+int main()
+{
+    {
+        typedef std::discrete_distribution<> D;
+        typedef D::result_type result_type;
+        static_assert((std::is_same<result_type, int>::value), "");
+    }
+    {
+        typedef std::discrete_distribution<long> D;
+        typedef D::result_type result_type;
+        static_assert((std::is_same<result_type, long>::value), "");
+    }
+}