61 lines
1.6 KiB
C++
61 lines
1.6 KiB
C++
/*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* Copyright 2010 Danny Robson <danny@nerdcruft.net>
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*/
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#ifndef __UTIL_RANDOM_HPP
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#define __UTIL_RANDOM_HPP
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#include <iterator>
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namespace util {
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template <typename T>
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T& randomise (T &);
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template <typename T, size_t N>
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T* randomise (T(&)[N]);
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template <typename T>
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T random (void);
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template <typename T>
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typename T::value_type&
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choose (T &container) {
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typename T::iterator cursor = container.begin ();
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typename T::size_type size = container.size ();
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typename T::size_type offset = random<typename T::size_type> () % size;
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std::advance (cursor, offset);
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return *cursor;
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}
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template <typename T, size_t N>
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T&
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choose (T (&v)[N]) {
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return v[static_cast<size_t> (random<float> () * N)];
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}
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template <typename T>
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typename T::value_type&
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choose (T begin, T end) {
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typename T::difference_type size = std::distance (begin, end);
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std::advance (begin, random<T::size_type> () % size);
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return *begin;
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}
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}
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#include "random.ipp"
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#endif
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