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| 5 | <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> |
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| 6 | |
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| 7 | <title>Boost Random Number Generator Library (Miscellaneous)</title> |
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| 8 | </head> |
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| 9 | |
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| 10 | <body bgcolor="#FFFFFF" text="#000000"> |
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| 11 | |
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| 12 | <h1>Random Number Generator Library --- Miscellaneous Decorators</h1> |
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| 13 | |
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| 14 | <ul> |
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| 15 | <li><a href="#random_number_generator">Class template |
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| 16 | <code>random_number_generator</code></a> |
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| 17 | </ul> |
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| 18 | |
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| 19 | <h2>Introduction</h2> |
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| 20 | |
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| 21 | These decorator class templates allow adaptation of the random number |
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| 22 | generators and distribution functions to concepts found in the C++ |
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| 23 | Standard Library, in particular the RandomNumberGenerator and the |
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| 24 | InputIterator concepts. The latter adaptation is useful, because the |
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| 25 | the basic random number generators do not implement the InputIterator |
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| 26 | requirements per se, in contrast to the distribution functions. |
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| 27 | |
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| 28 | |
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| 29 | <h2><a name="synopsis">Synopsis</a> of miscellaneous decorators in |
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| 30 | header <code><boost/random.hpp></code></h2> |
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| 31 | |
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| 32 | <pre> |
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| 33 | namespace boost { |
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| 34 | template<class UniformRandomNumberGenerator, class IntType = long> |
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| 35 | class random_number_generator; |
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| 36 | } // namespace boost |
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| 37 | </pre> |
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| 38 | |
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| 39 | |
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| 40 | <h2><a name="random_number_generator">Class template |
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| 41 | <code>random_number_generator</code></a></h2> |
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| 42 | |
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| 43 | <h3>Synopsis</h3> |
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| 44 | <pre> |
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| 45 | template<class UniformRandomNumberGenerator, class IntType = long> |
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| 46 | class random_number_generator |
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| 47 | { |
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| 48 | public: |
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| 49 | typedef UniformRandomNumberGenerator base_type; |
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| 50 | typedef IntType argument_type; |
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| 51 | typedef IntType result_type; |
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| 52 | random_number_generator(base_type & rng); |
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| 53 | result_type operator()(argument_type n); |
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| 54 | }; |
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| 55 | </pre> |
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| 56 | |
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| 57 | <h3>Description</h3> |
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| 58 | |
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| 59 | Instantiations of class template <code>random_number_generator</code> |
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| 60 | model a RandomNumberGenerator (std:25.2.11 [lib.alg.random.shuffle]). |
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| 61 | On each invocation, it returns a uniformly distributed integer in |
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| 62 | the range [0..<code>n</code>). |
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| 63 | <p> |
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| 64 | The template parameter <code>IntType</code> shall denote some |
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| 65 | integer-like value type. |
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| 66 | <p> |
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| 67 | |
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| 68 | <em>Note:</em> I consider it unfortunate that the C++ Standard uses |
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| 69 | the name RandomNumberGenerator for something rather specific. |
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| 70 | |
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| 71 | <h3>Members</h3> |
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| 72 | |
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| 73 | <pre>random_number_generator(base_type & rng)</pre> |
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| 74 | |
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| 75 | <strong>Effects:</strong> Constructs a |
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| 76 | <code>random_number_generator</code> functor with the given uniform |
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| 77 | random number generator as the underlying source of random numbers. |
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| 78 | |
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| 79 | <pre>result_type operator()(argument_type n)</pre> |
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| 80 | |
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| 81 | <strong>Returns:</strong> The value of |
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| 82 | <code>uniform_int<base_type>(rng, 0, n-1)()</code>. |
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| 83 | |
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| 84 | <p> |
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| 85 | <hr> |
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| 86 | Jens Maurer, 2001-11-19 |
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| 87 | |
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| 88 | </body> |
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| 89 | </html> |
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