[rand.dist.norm.normal]

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@103646 91177308-0d34-0410-b5e6-96231b3b80d8

include/random

@@ -686,16 +686,16 @@ public:
     public:
         typedef exponential_distribution distribution_type;
 
-        explicit param_type(RealType lambda = 1.0);
+        explicit param_type(result_type lambda = 1.0);
 
-        RealType lambda() const;
+        result_type lambda() const;
 
         friend bool operator==(const param_type& x, const param_type& y);
         friend bool operator!=(const param_type& x, const param_type& y);
     };
 
     // constructors and reset functions
-    explicit exponential_distribution(RealType lambda = 1.0);
+    explicit exponential_distribution(result_type lambda = 1.0);
     explicit exponential_distribution(const param_type& parm);
     void reset();
 
@@ -704,7 +704,7 @@ public:
     template<class URNG> result_type operator()(URNG& g, const param_type& parm);
 
     // property functions
-    RealType lambda() const;
+    result_type lambda() const;
 
     param_type param() const;
     void param(const param_type& parm);
@@ -740,7 +740,62 @@ template<class RealType = double>
     class extreme_value_distribution;
 
 template<class RealType = double>
-    class normal_distribution;
+class normal_distribution
+{
+public:
+    // types
+    typedef RealType result_type;
+
+    class param_type
+    {
+    public:
+        typedef normal_distribution distribution_type;
+
+        explicit param_type(result_type mean = 0, result_type stddev = 1);
+
+        result_type mean() const;
+        result_type stddev() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructors and reset functions
+    explicit normal_distribution(result_type mean = 0, result_type stddev = 1);
+    explicit normal_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
+    result_type mean() const;
+    result_type stddev() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const normal_distribution& x,
+                           const normal_distribution& y);
+    friend bool operator!=(const normal_distribution& x,
+                           const normal_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const normal_distribution& x);
+    
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               normal_distribution& x);
+};
 
 template<class RealType = double>
     class lognormal_distribution;
@@ -3171,6 +3226,155 @@ operator>>(basic_istream<_CharT, _Traits>& __is,
     return __is;
 }
 
+// normal_distribution
+
+template<class _RealType = double>
+class normal_distribution
+{
+public:
+    // types
+    typedef _RealType result_type;
+
+    class param_type
+    {
+        result_type __mean_;
+        result_type __stddev_;
+    public:
+        typedef normal_distribution distribution_type;
+
+        explicit param_type(result_type __mean = 0, result_type __stddev = 1)
+            : __mean_(__mean), __stddev_(__stddev) {}
+
+        result_type mean() const {return __mean_;}
+        result_type stddev() const {return __stddev_;}
+
+        friend bool operator==(const param_type& __x, const param_type& __y)
+            {return __x.__mean_ == __y.__mean_ && __x.__stddev_ == __y.__stddev_;}
+        friend bool operator!=(const param_type& __x, const param_type& __y)
+            {return !(__x == __y);}
+    };
+
+private:
+    param_type __p_;
+    result_type _V_;
+    bool _V_hot_;
+
+public:
+    // constructors and reset functions
+    explicit normal_distribution(result_type __mean = 0, result_type __stddev = 1)
+        : __p_(param_type(__mean, __stddev)), _V_hot_(false) {}
+    explicit normal_distribution(const param_type& __p)
+        : __p_(__p), _V_hot_(false) {}
+    void reset() {_V_hot_ = false;}
+
+    // 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
+    result_type mean() const {return __p_.mean();}
+    result_type stddev() const {return __p_.stddev();}
+
+    param_type param() const {return __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();}
+
+    friend bool operator==(const normal_distribution& __x,
+                           const normal_distribution& __y)
+        {return __x.__p_ == __y.__p_ && __x._V_hot_ == __y._V_hot_ &&
+                (!__x._V_hot_ || __x._V_ == __y._V_);}
+    friend bool operator!=(const normal_distribution& __x,
+                           const normal_distribution& __y)
+            {return !(__x == __y);}
+
+    template <class _CharT, class _Traits, class _RT>
+    friend
+    basic_ostream<_CharT, _Traits>&
+    operator<<(basic_ostream<_CharT, _Traits>& __os,
+               const normal_distribution<_RT>& __x);
+    
+    template <class _CharT, class _Traits, class _RT>
+    friend
+    basic_istream<_CharT, _Traits>&
+    operator>>(basic_istream<_CharT, _Traits>& __is,
+               normal_distribution<_RT>& __x);
+};
+
+template <class _RealType>
+template<class _URNG>
+_RealType
+normal_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
+{
+    result_type _U;
+    if (_V_hot_)
+    {
+        _V_hot_ = false;
+        _U = _V_;
+    }
+    else
+    {
+        uniform_real_distribution<result_type> _Uni(-1, 1);
+        result_type __u;
+        result_type __v;
+        result_type __s;
+        do
+        {
+            __u = _Uni(__g);
+            __v = _Uni(__g);
+            __s = __u * __u + __v * __v;
+        } while (__s > 1 || __s == 0);
+        result_type _F = _STD::sqrt(-2 * _STD::log(__s) / __s);
+        _V_ = __v * _F;
+        _V_hot_ = true;
+        _U = __u * _F;
+    }
+    return _U * __p.stddev() + __p.mean();
+}
+
+template <class _CharT, class _Traits, class _RT>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os,
+           const normal_distribution<_RT>& __x)
+{
+    __save_flags<_CharT, _Traits> _(__os);
+    __os.flags(ios_base::dec | ios_base::left);
+    _CharT __sp = __os.widen(' ');
+    __os.fill(__sp);
+    __os << __x.mean() << __sp << __x.stddev() << __sp << __x._V_hot_;
+    if (__x._V_hot_)
+        __os << __sp << __x._V_;
+    return __os;
+}
+
+template <class _CharT, class _Traits, class _RT>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is,
+           normal_distribution<_RT>& __x)
+{
+    typedef normal_distribution<_RT> _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);
+    result_type __mean;
+    result_type __stddev;
+    result_type _V = 0;
+    bool _V_hot = false;
+    __is >> __mean >> __stddev >> _V_hot;
+    if (_V_hot)
+        __is >> _V;
+    if (!__is.fail())
+    {
+        __x.param(param_type(__mean, __stddev));
+        __x._V_hot_ = _V_hot;
+        __x._V_ = _V;
+    }
+    return __is;
+}
+
 _LIBCPP_END_NAMESPACE_STD
 
 #endif  // _LIBCPP_RANDOM

test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/assign.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 RealType = double>
+// class normal_distribution
+
+// normal_distribution& operator=(const normal_distribution&);
+
+#include <random>
+#include <cassert>
+
+void
+test1()
+{
+    typedef std::normal_distribution<> D;
+    D d1(20, 0.75);
+    D d2;
+    assert(d1 != d2);
+    d2 = d1;
+    assert(d1 == d2);
+}
+
+int main()
+{
+    test1();
+}

test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/copy.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 RealType = double>
+// class normal_distribution
+
+// normal_distribution(const normal_distribution&);
+
+#include <random>
+#include <cassert>
+
+void
+test1()
+{
+    typedef std::normal_distribution<> D;
+    D d1(20, 1.75);
+    D d2 = d1;
+    assert(d1 == d2);
+}
+
+int main()
+{
+    test1();
+}

test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/ctor_double_double.pass.cpp

@@ -0,0 +1,40 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class RealType = double>
+// class normal_distribution
+
+// explicit normal_distribution(result_type mean = 0, result_type stddev = 1);
+
+#include <random>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::normal_distribution<> D;
+        D d;
+        assert(d.mean() == 0);
+        assert(d.stddev() == 1);
+    }
+    {
+        typedef std::normal_distribution<> D;
+        D d(14.5);
+        assert(d.mean() == 14.5);
+        assert(d.stddev() == 1);
+    }
+    {
+        typedef std::normal_distribution<> D;
+        D d(14.5, 5.25);
+        assert(d.mean() == 14.5);
+        assert(d.stddev() == 5.25);
+    }
+}

test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/ctor_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 RealType = double>
+// class normal_distribution
+
+// explicit normal_distribution(const param_type& parm);
+
+#include <random>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::normal_distribution<> D;
+        typedef D::param_type P;
+        P p(0.25, 10);
+        D d(p);
+        assert(d.mean() == 0.25);
+        assert(d.stddev() == 10);
+    }
+}

test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/eq.pass.cpp

@@ -0,0 +1,37 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class RealType = double>
+// class normal_distribution
+
+// bool operator=(const normal_distribution& x,
+//                const normal_distribution& y);
+// bool operator!(const normal_distribution& x,
+//                const normal_distribution& y);
+
+#include <random>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::normal_distribution<> D;
+        D d1(2.5, 4);
+        D d2(2.5, 4);
+        assert(d1 == d2);
+    }
+    {
+        typedef std::normal_distribution<> D;
+        D d1(2.5, 4);
+        D d2(2.5, 4.5);
+        assert(d1 != d2);
+    }
+}

test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/eval.pass.cpp

@@ -0,0 +1,53 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class RealType = double>
+// class normal_distribution
+
+// template<class _URNG> result_type operator()(_URNG& g);
+
+#include <random>
+#include <cassert>
+#include <vector>
+#include <numeric>
+
+template <class T>
+inline
+T
+sqr(T x)
+{
+    return x * x;
+}
+
+int main()
+{
+    {
+        typedef std::normal_distribution<> D;
+        typedef D::param_type P;
+        typedef std::minstd_rand G;
+        G g;
+        D d(5, 4);
+        const int N = 1000;
+        std::vector<D::result_type> u;
+        for (int i = 0; i < N; ++i)
+            u.push_back(d(g));
+        D::result_type mean = std::accumulate(u.begin(), u.end(),
+                                              D::result_type(0)) / u.size();
+        D::result_type var = 0;
+        for (int i = 0; i < u.size(); ++i)
+            var += sqr(u[i] - mean);
+        var /= u.size();
+        D::result_type x_mean = d.mean();
+        D::result_type x_var = sqr(d.stddev());
+        assert(std::abs(mean - x_mean) / x_mean < 0.01);
+        assert(std::abs(var - x_var) / x_var < 0.01);
+    }
+}

test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/eval_param.pass.cpp

@@ -0,0 +1,54 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class RealType = double>
+// class normal_distribution
+
+// template<class _URNG> result_type operator()(_URNG& g, const param_type& parm);
+
+#include <random>
+#include <cassert>
+#include <vector>
+#include <numeric>
+
+template <class T>
+inline
+T
+sqr(T x)
+{
+    return x * x;
+}
+
+int main()
+{
+    {
+        typedef std::normal_distribution<> D;
+        typedef D::param_type P;
+        typedef std::minstd_rand G;
+        G g;
+        D d(5, 4);
+        P p(50, .5);
+        const int N = 1000;
+        std::vector<D::result_type> u;
+        for (int i = 0; i < N; ++i)
+            u.push_back(d(g, p));
+        D::result_type mean = std::accumulate(u.begin(), u.end(),
+                                              D::result_type(0)) / u.size();
+        D::result_type var = 0;
+        for (int i = 0; i < u.size(); ++i)
+            var += sqr(u[i] - mean);
+        var /= u.size();
+        D::result_type x_mean = p.mean();
+        D::result_type x_var = sqr(p.stddev());
+        assert(std::abs(mean - x_mean) / x_mean < 0.01);
+        assert(std::abs(var - x_var) / x_var < 0.01);
+    }
+}

test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/get_param.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 RealType = double>
+// class normal_distribution
+
+// param_type param() const;
+
+#include <random>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::normal_distribution<> D;
+        typedef D::param_type P;
+        P p(.125, .5);
+        D d(p);
+        assert(d.param() == p);
+    }
+}

test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/io.pass.cpp

@@ -0,0 +1,41 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class RealType = double>
+// class normal_distribution
+
+// template <class CharT, class Traits, class RealType>
+// basic_ostream<CharT, Traits>&
+// operator<<(basic_ostream<CharT, Traits>& os,
+//            const normal_distribution<RealType>& x);
+
+// template <class CharT, class Traits, class RealType>
+// basic_istream<CharT, Traits>&
+// operator>>(basic_istream<CharT, Traits>& is,
+//            normal_distribution<RealType>& x);
+
+#include <random>
+#include <sstream>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::normal_distribution<> D;
+        D d1(7, 5);
+        std::ostringstream os;
+        os << d1;
+        std::istringstream is(os.str());
+        D d2;
+        is >> d2;
+        assert(d1 == d2);
+    }
+}

test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/max.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 RealType = double>
+// class normal_distribution
+
+// result_type max() const;
+
+#include <random>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::normal_distribution<> D;
+        D d(5, .25);
+        D::result_type m = d.max();
+        assert(m == INFINITY);
+    }
+}

test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/min.pass.cpp

@@ -0,0 +1,27 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class RealType = double>
+// class normal_distribution
+
+// result_type min() const;
+
+#include <random>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::normal_distribution<> D;
+        D d(.5, .5);
+        assert(d.min() == -INFINITY);
+    }
+}

test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/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 RealType = double>
+// class normal_distribution
+// {
+//     class param_type;
+
+#include <random>
+#include <limits>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::normal_distribution<> D;
+        typedef D::param_type param_type;
+        param_type p0(.75, 6);
+        param_type p;
+        p = p0;
+        assert(p.mean() == .75);
+        assert(p.stddev() == 6);
+    }
+}

test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/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 RealType = double>
+// class normal_distribution
+// {
+//     class param_type;
+
+#include <random>
+#include <limits>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::normal_distribution<> D;
+        typedef D::param_type param_type;
+        param_type p0(10, .125);
+        param_type p = p0;
+        assert(p.mean() == 10);
+        assert(p.stddev() == .125);
+    }
+}

test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/param_ctor.pass.cpp

@@ -0,0 +1,44 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class RealType = double>
+// class normal_distribution
+// {
+//     class param_type;
+
+#include <random>
+#include <limits>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::normal_distribution<> D;
+        typedef D::param_type param_type;
+        param_type p;
+        assert(p.mean() == 0);
+        assert(p.stddev() == 1);
+    }
+    {
+        typedef std::normal_distribution<> D;
+        typedef D::param_type param_type;
+        param_type p(10);
+        assert(p.mean() == 10);
+        assert(p.stddev() == 1);
+    }
+    {
+        typedef std::normal_distribution<> D;
+        typedef D::param_type param_type;
+        param_type p(10, 5);
+        assert(p.mean() == 10);
+        assert(p.stddev() == 5);
+    }
+}

test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/param_eq.pass.cpp

@@ -0,0 +1,37 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template<class RealType = double>
+// class normal_distribution
+// {
+//     class param_type;
+
+#include <random>
+#include <limits>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::normal_distribution<> D;
+        typedef D::param_type param_type;
+        param_type p1(0.75, .5);
+        param_type p2(0.75, .5);
+        assert(p1 == p2);
+    }
+    {
+        typedef std::normal_distribution<> D;
+        typedef D::param_type param_type;
+        param_type p1(0.75, .5);
+        param_type p2(0.5, .5);
+        assert(p1 != p2);
+    }
+}

test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/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 RealType = double>
+// class normal_distribution
+// {
+//     class param_type;
+
+#include <random>
+#include <type_traits>
+
+int main()
+{
+    {
+        typedef std::normal_distribution<> D;
+        typedef D::param_type param_type;
+        typedef param_type::distribution_type distribution_type;
+        static_assert((std::is_same<D, distribution_type>::value), "");
+    }
+}

test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/set_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 RealType = double>
+// class normal_distribution;
+
+// void param(const param_type& parm);
+
+#include <random>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::normal_distribution<> D;
+        typedef D::param_type P;
+        P p(0.25, 5.5);
+        D d(0.75, 4);
+        d.param(p);
+        assert(d.param() == p);
+    }
+}

test/numerics/rand/rand.dis/rand.dist.norm/rand.dist.norm.normal/types.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 RealType = double>
+// class normal_distribution
+// {
+// public:
+//     // types
+//     typedef RealType result_type;
+
+#include <random>
+#include <type_traits>
+
+int main()
+{
+    {
+        typedef std::normal_distribution<> D;
+        typedef D::result_type result_type;
+        static_assert((std::is_same<result_type, double>::value), "");
+    }
+    {
+        typedef std::normal_distribution<float> D;
+        typedef D::result_type result_type;
+        static_assert((std::is_same<result_type, float>::value), "");
+    }
+}