Add a simple fixed size list class

2 files changed, 146 insertions, 0 deletions

diff --git a/include/axolotl/list.hh b/include/axolotl/list.hh
new file mode 100644
index 0000000..b76abdd
--- /dev/null
+++ b/include/axolotl/list.hh
@@ -0,0 +1,90 @@
+#include <cstddef>
+
+namespace axolotl {
+
+template<typename T, std::size_t max_size>
+class List {
+public:
+    List() : _end(_data) {}
+
+    typedef T * iterator;
+    typedef T const * const_iterator;
+
+    T * begin() { return _data; }
+    T * end() { return _end; }
+    T const * begin() const { return _data; }
+    T const * end() const { return _end; }
+
+    /**
+     * The number of items in the list.
+     */
+    std::size_t size() { return _end - _data; }
+
+    T & operator[](std::size_t index) { return _data[index]; }
+
+    T const & operator[](std::size_t index) const { return _data[index]; }
+
+    /**
+     * Erase the item from the list at the given position.
+     */
+    void erase(T * pos) {
+        --_end;
+        while (pos != _end) {
+            *pos = *(pos + 1);
+            ++pos;
+        }
+    }
+
+    /**
+     * Make space for an item in the list at a given position.
+     * If inserting the item makes the list longer than max_size then
+     * the end of the list is discarded.
+     * Returns the where the item is inserted.
+     */
+    T * insert(T * pos) {
+        if (_end != _data + max_size) {
+            ++_end;
+        } else if (pos == _end) {
+            --pos;
+        }
+        T * tmp = pos;
+        while (tmp != _end - 1) {
+            *(tmp + 1) = *tmp;
+            ++tmp;
+        }
+        return pos;
+    }
+
+    /**
+     * Insert an item into the list at a given position.
+     * If inserting the item makes the list longer than max_size then
+     * the end of the list is discarded.
+     * Returns the where the item is inserted.
+     */
+    T * insert(T * pos, T const & value) {
+        pos = insert(pos);
+        *pos = value;
+        return pos;
+    }
+
+    List<T, max_size> & operator=(List<T, max_size> const & other) {
+        if (this = &other) {
+            return *this;
+        }
+        T * this_pos = _data;
+        T * const other_pos = other._data;
+        while (other_pos != other._end) {
+            *this_pos = *other;
+            ++this_pos;
+            ++other_pos;
+        }
+        _end = this_pos;
+        return *this;
+    }
+
+private:
+    T * _end;
+    T _data[max_size];
+};
+
+} // namespace axolotl
diff --git a/tests/test_list.cpp b/tests/test_list.cpp
new file mode 100644
index 0000000..27b3d58
--- /dev/null
+++ b/tests/test_list.cpp
@@ -0,0 +1,56 @@
+#include "axolotl/list.hh"
+#include "unittest.hh"
+
+int main() {
+
+{ /** List insert test **/
+
+TestCase test_case("List insert");
+
+axolotl::List<int, 4> test_list;
+
+assert_equals(std::size_t(0), test_list.size());
+
+for (int i = 0; i < 4; ++i) {
+    test_list.insert(test_list.end(), i);
+}
+
+assert_equals(std::size_t(4), test_list.size());
+
+int i = 0;
+for (auto item : test_list) {
+    assert_equals(i++, item);
+}
+
+assert_equals(4, i);
+
+test_list.insert(test_list.end(), 4);
+
+assert_equals(4, test_list[3]);
+
+} /** List insert test **/
+
+{ /** List erase test **/
+TestCase test_case("List erase");
+
+axolotl::List<int, 4> test_list;
+assert_equals(std::size_t(0), test_list.size());
+
+for (int i = 0; i < 4; ++i) {
+    test_list.insert(test_list.end(), i);
+}
+assert_equals(std::size_t(4), test_list.size());
+
+test_list.erase(test_list.begin());
+assert_equals(std::size_t(3), test_list.size());
+
+int i = 0;
+for (auto item : test_list) {
+    assert_equals(i + 1, item);
+    ++i;
+}
+assert_equals(3, i);
+
+}
+
+}