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/* Self tests for the filtered_iterator class.
Copyright (C) 2019-2020 Free Software Foundation, Inc.
This file is part of GDB.
This program 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 of the License, or
(at your option) any later version.
This program 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 program. If not, see <http://www.gnu.org/licenses/>. */
#include "gdbsupport/common-defs.h"
#include "gdbsupport/selftest.h"
#include "gdbsupport/filtered-iterator.h"
#include <iterator>
namespace selftests {
/* An iterator class that iterates on integer arrays. */
struct int_array_iterator
{
using value_type = int;
using reference = int &;
using pointer = int *;
using iterator_category = std::forward_iterator_tag;
using difference_type = int;
/* Create an iterator that points at the first element of an integer
array at ARRAY of size SIZE. */
int_array_iterator (int *array, size_t size)
: m_array (array), m_size (size)
{}
/* Create a past-the-end iterator. */
int_array_iterator ()
: m_array (nullptr), m_size (0)
{}
bool operator== (const int_array_iterator &other) const
{
/* If both are past-the-end, they are equal. */
if (m_array == nullptr && other.m_array == nullptr)
return true;
/* If just one of them is past-the-end, they are not equal. */
if (m_array == nullptr || other.m_array == nullptr)
return false;
/* If they are both not past-the-end, make sure they iterate on the
same array (we shouldn't compare iterators that iterate on different
things). */
gdb_assert (m_array == other.m_array);
/* They are equal if they have the same current index. */
return m_cur_idx == other.m_cur_idx;
}
bool operator!= (const int_array_iterator &other) const
{
return !(*this == other);
}
void operator++ ()
{
/* Make sure nothing tries to increment a past the end iterator. */
gdb_assert (m_cur_idx < m_size);
m_cur_idx++;
/* Mark the iterator as "past-the-end" if we have reached the end. */
if (m_cur_idx == m_size)
m_array = nullptr;
}
int operator* () const
{
/* Make sure nothing tries to dereference a past the end iterator. */
gdb_assert (m_cur_idx < m_size);
return m_array[m_cur_idx];
}
private:
/* A nullptr value in M_ARRAY indicates a past-the-end iterator. */
int *m_array;
size_t m_size;
size_t m_cur_idx = 0;
};
/* Filter to only keep the even numbers. */
struct even_numbers_only
{
bool operator() (int n)
{
return n % 2 == 0;
}
};
/* Test typical usage. */
static void
test_filtered_iterator ()
{
int array[] = { 4, 4, 5, 6, 7, 8, 9 };
std::vector<int> even_ints;
const std::vector<int> expected_even_ints { 4, 4, 6, 8 };
filtered_iterator<int_array_iterator, even_numbers_only>
iter (array, ARRAY_SIZE (array));
filtered_iterator<int_array_iterator, even_numbers_only> end;
for (; iter != end; ++iter)
even_ints.push_back (*iter);
gdb_assert (even_ints == expected_even_ints);
}
/* Test operator== and operator!=. */
static void
test_filtered_iterator_eq ()
{
int array[] = { 4, 4, 5, 6, 7, 8, 9 };
filtered_iterator<int_array_iterator, even_numbers_only>
iter1(array, ARRAY_SIZE (array));
filtered_iterator<int_array_iterator, even_numbers_only>
iter2(array, ARRAY_SIZE (array));
/* They start equal. */
gdb_assert (iter1 == iter2);
gdb_assert (!(iter1 != iter2));
/* Advance 1, now they aren't equal (despite pointing to equal values). */
++iter1;
gdb_assert (!(iter1 == iter2));
gdb_assert (iter1 != iter2);
/* Advance 2, now they are equal again. */
++iter2;
gdb_assert (iter1 == iter2);
gdb_assert (!(iter1 != iter2));
}
} /* namespace selftests */
void _initialize_filtered_iterator_selftests ();
void
_initialize_filtered_iterator_selftests ()
{
selftests::register_test ("filtered_iterator",
selftests::test_filtered_iterator);
selftests::register_test ("filtered_iterator_eq",
selftests::test_filtered_iterator_eq);
}
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