# 28 Numerics library [numerics]

## 28.5 Random number generation [rand]

### 28.5.9 Random number distribution class templates [rand.dist]

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

A uniform_int_distribution random number distribution produces random integers i, a  ≤ i  ≤ b, distributed according to the constant discrete probability function
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); }; }
```explicit uniform_int_distribution(IntType a, IntType b = numeric_limits<IntType>::max()); ```
Preconditions: a  ≤ b.
Remarks: a and b correspond to the respective parameters of the distribution.
```result_type a() const; ```
Returns: The value of the a parameter with which the object was constructed.
```result_type b() const; ```
Returns: The value of the b parameter with which the object was constructed.