28 Numerics library [numerics]

28.5 Random number generation [rand]

28.5.9 Random number distribution class templates [rand.dist]

28.5.9.2 Uniform distributions [rand.dist.uni]

28.5.9.2.1 Class template uniform_int_distribution [rand.dist.uni.int]

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A uniform_int_distribution random number distribution produces random integers i, a  ≤ i  ≤ b, distributed according to the constant discrete probability function
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namespace std { template<class IntType = int> class uniform_int_distribution { public: // types using result_type = IntType; using param_type = unspecified; // constructors and reset functions uniform_int_distribution() : uniform_int_distribution(0) {} explicit uniform_int_distribution(IntType a, IntType b = numeric_limits<IntType>::max()); explicit uniform_int_distribution(const param_type& parm); void reset(); // equality operators friend bool operator==(const uniform_int_distribution& x, const uniform_int_distribution& y); // generating functions template<class URBG> result_type operator()(URBG& g); template<class URBG> result_type operator()(URBG& g, const param_type& parm); // property functions result_type a() const; result_type b() const; param_type param() const; void param(const param_type& parm); result_type min() const; result_type max() const; // inserters and extractors template<class charT, class traits> friend basic_ostream<charT, traits>& operator<<(basic_ostream<charT, traits>& os, const uniform_int_distribution& x); template<class charT, class traits> friend basic_istream<charT, traits>& operator>>(basic_istream<charT, traits>& is, uniform_int_distribution& x); }; }
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explicit uniform_int_distribution(IntType a, IntType b = numeric_limits<IntType>::max());
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Preconditions: a  ≤ b.
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Remarks: a and b correspond to the respective parameters of the distribution.
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result_type a() const;
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Returns: The value of the a parameter with which the object was constructed.
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result_type b() const;
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Returns: The value of the b parameter with which the object was constructed.

28.5.9.2.2 Class template uniform_real_distribution [rand.dist.uni.real]

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A uniform_real_distribution random number distribution produces random numbers x, , distributed according to the constant probability density function
[Note 1: 
This implies that p(x | a,b) is undefined when a == b.
— end note]
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namespace std { template<class RealType = double> class uniform_real_distribution { public: // types using result_type = RealType; using param_type = unspecified; // constructors and reset functions uniform_real_distribution() : uniform_real_distribution(0.0) {} explicit uniform_real_distribution(RealType a, RealType b = 1.0); explicit uniform_real_distribution(const param_type& parm); void reset(); // equality operators friend bool operator==(const uniform_real_distribution& x, const uniform_real_distribution& y); // generating functions template<class URBG> result_type operator()(URBG& g); template<class URBG> result_type operator()(URBG& g, const param_type& parm); // property functions result_type a() const; result_type b() const; param_type param() const; void param(const param_type& parm); result_type min() const; result_type max() const; // inserters and extractors template<class charT, class traits> friend basic_ostream<charT, traits>& operator<<(basic_ostream<charT, traits>& os, const uniform_real_distribution& x); template<class charT, class traits> friend basic_istream<charT, traits>& operator>>(basic_istream<charT, traits>& is, uniform_real_distribution& x); }; }
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explicit uniform_real_distribution(RealType a, RealType b = 1.0);
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Preconditions: a  ≤ b and .
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Remarks: a and b correspond to the respective parameters of the distribution.
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result_type a() const;
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Returns: The value of the a parameter with which the object was constructed.
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result_type b() const;
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Returns: The value of the b parameter with which the object was constructed.