aboutsummaryrefslogtreecommitdiff
path: root/libstdc++-v3/testsuite/ext/pb_ds/example/hash_illegal_resize.cc
diff options
context:
space:
mode:
Diffstat (limited to 'libstdc++-v3/testsuite/ext/pb_ds/example/hash_illegal_resize.cc')
-rw-r--r--libstdc++-v3/testsuite/ext/pb_ds/example/hash_illegal_resize.cc137
1 files changed, 137 insertions, 0 deletions
diff --git a/libstdc++-v3/testsuite/ext/pb_ds/example/hash_illegal_resize.cc b/libstdc++-v3/testsuite/ext/pb_ds/example/hash_illegal_resize.cc
new file mode 100644
index 00000000000..9b3e7747488
--- /dev/null
+++ b/libstdc++-v3/testsuite/ext/pb_ds/example/hash_illegal_resize.cc
@@ -0,0 +1,137 @@
+// -*- C++ -*-
+
+// Copyright (C) 2005, 2006 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, 59 Temple Place - Suite 330, Boston,
+// MA 02111-1307, 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_illegal_resize_example.cpp
+ * An example of illegally
+ * externally resizing a hash-based container object.
+ */
+
+/**
+ * This example shows the case where a hash-based container object is
+ * resized to a value which it cannot accomodate at runtime. Illegal
+ * runtime resizes cause an exception.
+ */
+
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/hash_policy.hpp>
+#include <ext/pb_ds/exception.hpp>
+#include <cassert>
+
+using namespace std;
+using namespace pb_ds;
+
+// 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()
+{
+ // A probing hash table mapping ints to chars.
+ typedef
+ gp_hash_table<
+ int,
+ int,
+ int_hash,
+ equal_to<
+ int>,
+ // Combining function.
+ direct_mod_range_hashing<>,
+ // Probe function.
+ quadratic_probe_fn<>,
+ // Resize policy.
+ hash_standard_resize_policy<
+ hash_prime_size_policy,
+ 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;
+
+ // Insert some elements.
+ int i;
+
+ for (i = 0; i < 1000; ++i)
+ g[i] = 2* i;
+
+ // Check all ok.
+ assert(g.size() == 1000);
+ for (i = 0; i < 1000; ++i)
+ assert(g.find(i) != g.end()&& g.find(i)->second == 2* i);
+
+ // Now attempt to resize the table to 200 (impossible).
+ bool ex_thrown = false;
+
+ try
+ {
+ g.resize(200);
+ }
+ catch(pb_ds::resize_error& )
+ {
+ ex_thrown = true;
+ }
+
+ // Assert an exception was thrown. A probing table cannot contain
+ // 1000 entries in less than 1000 places.
+ assert(ex_thrown);
+
+ // Irrespective of the fact that the resize was not successful, the
+ // container object should still be in a valid state; the following
+ // checks this.
+ // Check all ok.
+ assert(g.size() == 1000);
+ for (i = 0; i < 1000; ++i)
+ assert(g.find(i) != g.end()&& g.find(i)->second == 2* i);
+
+ return 0;
+}
+