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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-13 11:57:42 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-13 11:57:42 +0000 |
commit | 61f3ab8f23f4c924d455757bf3e65f8487521b5a (patch) | |
tree | 885599a36a308f422af98616bc733a0494fe149a /include/2geom/utils.h | |
parent | Initial commit. (diff) | |
download | lib2geom-61f3ab8f23f4c924d455757bf3e65f8487521b5a.tar.xz lib2geom-61f3ab8f23f4c924d455757bf3e65f8487521b5a.zip |
Adding upstream version 1.3.upstream/1.3upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | include/2geom/utils.h | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/include/2geom/utils.h b/include/2geom/utils.h new file mode 100644 index 0000000..87f49bb --- /dev/null +++ b/include/2geom/utils.h @@ -0,0 +1,114 @@ +/** + * \file + * \brief Various utility functions. + *//* + * Copyright 2007 Johan Engelen <goejendaagh@zonnet.nl> + * Copyright 2006 Michael G. Sloan <mgsloan@gmail.com> + * + * This library is free software; you can redistribute it and/or + * modify it either under the terms of the GNU Lesser General Public + * License version 2.1 as published by the Free Software Foundation + * (the "LGPL") or, at your option, under the terms of the Mozilla + * Public License Version 1.1 (the "MPL"). If you do not alter this + * notice, a recipient may use your version of this file under either + * the MPL or the LGPL. + * + * You should have received a copy of the LGPL along with this library + * in the file COPYING-LGPL-2.1; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * You should have received a copy of the MPL along with this library + * in the file COPYING-MPL-1.1 + * + * The contents of this file are subject to the Mozilla Public License + * Version 1.1 (the "License"); you may not use this file except in + * compliance with the License. You may obtain a copy of the License at + * http://www.mozilla.org/MPL/ + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY + * OF ANY KIND, either express or implied. See the LGPL or the MPL for + * the specific language governing rights and limitations. + * + */ + +#ifndef LIB2GEOM_SEEN_UTILS_H +#define LIB2GEOM_SEEN_UTILS_H + +#include <cstddef> +#include <vector> +#include <boost/operators.hpp> + +namespace Geom { + +// Throw these errors instead of aserting so code can handle them if needed. +using ErrorCode = int; +enum Errors : ErrorCode { + GEOM_ERR_INTERSECGRAPH, +}; + +void binomial_coefficients(std::vector<size_t>& bc, std::size_t n); + +struct EmptyClass {}; + +/** + * @brief Noncommutative multiplication helper. + * Generates operator*(T, U) from operator*=(T, U). Does not generate operator*(U, T) + * like boost::multipliable does. This makes it suitable for noncommutative cases, + * such as transforms. + */ +template <class T, class U, class B = EmptyClass> +struct MultipliableNoncommutative : B +{ + friend T operator*(T const &lhs, U const &rhs) { + T nrv(lhs); nrv *= rhs; return nrv; + } +}; + +/** @brief Null output iterator + * Use this if you want to discard a result returned through an output iterator. */ +struct NullIterator + : public boost::output_iterator_helper<NullIterator> +{ + NullIterator() {} + + template <typename T> + void operator=(T const &) {} +}; + +/** @brief Get the next iterator in the container with wrap-around. + * If the iterator would become the end iterator after incrementing, + * return the begin iterator instead. */ +template <typename Iter, typename Container> +Iter cyclic_next(Iter i, Container &c) { + ++i; + if (i == c.end()) { + i = c.begin(); + } + return i; +} + +/** @brief Get the previous iterator in the container with wrap-around. + * If the passed iterator is the begin iterator, return the iterator + * just before the end iterator instead. */ +template <typename Iter, typename Container> +Iter cyclic_prior(Iter i, Container &c) { + if (i == c.begin()) { + i = c.end(); + } + --i; + return i; +} + +} // end namespace Geom + +#endif // LIB2GEOM_SEEN_UTILS_H + +/* + Local Variables: + mode:c++ + c-file-style:"stroustrup" + c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +)) + indent-tabs-mode:nil + fill-column:99 + End: +*/ +// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 : |