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[/] [scarts/] [trunk/] [toolchain/] [scarts-gcc/] [gcc-4.1.1/] [libstdc++-v3/] [testsuite/] [ext/] [pb_assoc/] [example/] [hash_resize.cc] - Rev 19
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// -*- C++ -*- // Copyright (C) 2005 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 2, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // You should have received a copy of the GNU General Public License along // with this library; see the file COPYING. If not, write to the Free // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, // USA. // As a special exception, you may use this file as part of a free software // library without restriction. Specifically, if other files instantiate // templates or use macros or inline functions from this file, or you compile // this file and link it with other files to produce an executable, this // file does not by itself cause the resulting executable to be covered by // the GNU General Public License. This exception does not however // invalidate any other reasons why the executable file might be covered by // the GNU General Public License. // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL. // Permission to use, copy, modify, sell, and distribute this software // is hereby granted without fee, provided that the above copyright // notice appears in all copies, and that both that copyright notice and // this permission notice appear in supporting documentation. None of // the above authors, nor IBM Haifa Research Laboratories, make any // representation about the suitability of this software for any // purpose. It is provided "as is" without express or implied warranty. /** * @file hash_resize_example.cpp * An example of externally resizing a map. */ // For gp_hash_assoc_cntnr. #include <ext/pb_assoc/assoc_cntnr.hpp> // For hash-related policies. #include <ext/pb_assoc/hash_policy.hpp> // For unary_function. #include <functional> // For assert #include <cassert> /* * A simple hash functor. * std::hash could serve instead of this functor, * but it is not yet standard everywhere. */ struct int_hash : public std::unary_function< int, size_t> { inline size_t operator()(const int& r_i) const { return (r_i); } }; int main() { /* * A probing hash table mapping ints to chars. */ typedef pb_assoc::gp_hash_assoc_cntnr< int, char, int_hash, std::equal_to< int>, // Combining function. pb_assoc::direct_mask_range_hashing<>, // Probe function. pb_assoc::linear_probe_fn< int>, // Resize policy. pb_assoc::hash_standard_resize_policy< pb_assoc::hash_exponential_size_policy<>, pb_assoc::hash_load_check_resize_trigger<>, /* Allow external access to size. * Without setting this to true, external resizing * is not possible. */ true> > map_t; map_t g; /* * Check the actual size of the container object. In this case, * this should be the initial size given by the size policy object. **/ assert(g.get_actual_size() == 8); // Insert some elements. g[1] = 'a'; g[2] = 'b'; g[3] = 'c'; // Now resize the table upward. g.resize(200); /* * Check the actual size of the container object. * For the policy used in this example, the * nearest larger size than 200 is 256. **/ assert(g.get_actual_size() == 256); g[67] = 'g'; g[22] = 'f'; // Regardless of the internal size, the logical size should be 5. assert(g.size() == 5); // Now resize the table downward. g.resize(106); /* * Check the actual size of the container object. * For the policy used in this example, the * nearest larger size than 106 is 128. **/ assert(g.get_actual_size() == 128); g[37] = 'f'; // Regardless of the internal size, the logical size should be 5. assert(g.size() == 6); }