URL
https://opencores.org/ocsvn/openrisc/openrisc/trunk
Subversion Repositories openrisc
[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [libstdc++-v3/] [testsuite/] [ext/] [pb_ds/] [example/] [hash_initial_size.cc] - Rev 776
Go to most recent revision | Compare with Previous | Blame | View Log
// -*- C++ -*- // Copyright (C) 2005, 2006, 2009 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 3, 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 COPYING3. If not see // <http://www.gnu.org/licenses/>. // 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_initial_size_example.cpp * An example of setting an initial size for a container object. */ /** * This example shows how to set the initial size of a hash-based * container object through its resize-policy object. */ #include <cassert> #include <ext/pb_ds/assoc_container.hpp> #include <ext/pb_ds/hash_policy.hpp> using namespace std; using namespace __gnu_pbds; // A simple hash functor. // hash could serve instead of this functor, but it is not yet // standard everywhere. struct int_hash : public unary_function<int, size_t> { inline size_t operator()(const int& r_i) const { return r_i; } }; int main() { // Resize policy type. typedef hash_standard_resize_policy< // Size-policy type. hash_exponential_size_policy<>, // Trigger-policy type. hash_load_check_resize_trigger<>, /* Allow external access to size. * This is just used in this example for using the * get_actual_size method (which won't be accessible without * this flag. */ true> resize_policy_t; // A collision-probing hash table mapping ints to chars. typedef gp_hash_table< int, char, int_hash, equal_to< int>, // Combining function. direct_mask_range_hashing<>, // Probe function. linear_probe_fn<>, // Resize policy. resize_policy_t> map_t; // A resize-policy object with suggested initial size 256. resize_policy_t res(hash_exponential_size_policy<>(256)); map_t g(int_hash(), equal_to<int>(), direct_mask_range_hashing<>(), linear_probe_fn<>(), res); // 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() == 256); // The logical size of g, though is 0 (it does not contain any elements). assert(g.size() == 0); return 0; }
Go to most recent revision | Compare with Previous | Blame | View Log