Add cvector_resize(vec, count) (#68)

* Add cvector_resize(vec, count)

* cvector_resize: Add value to initialize new elements

* cvector_resize: Fix clang-format

README.md

@@ -113,5 +113,6 @@ int main(int argc, char *argv[]) {
 | [`v.push_back(value)`](https://en.cppreference.com/w/cpp/container/vector/push_back) | `cvector_push_back(v, value)` |
 | [`v.pop_back()`](https://en.cppreference.com/w/cpp/container/vector/pop_back) | `cvector_pop_back(v)` |
 | [`v.reserve(new_cap)`](https://en.cppreference.com/w/cpp/container/vector/reserve) | `cvector_reserve(v, new_cap)` |
+| [`v.resize(count)`](https://en.cppreference.com/w/cpp/container/vector/resize) | `cvector_resize(v, count)` |
 | [`v.swap(other)`](https://en.cppreference.com/w/cpp/container/vector/swap) | `cvector_swap(v, other)` |
 | [`std::vector<int> other = v;`](https://en.cppreference.com/w/cpp/named_req/CopyConstructible) | `cvector(int) other; cvector_copy(v, other);` |

cvector.h

@@ -450,4 +450,30 @@ typedef struct cvector_metadata_t {
 #define cvector_back(vec) \
     ((vec) ? ((cvector_size(vec) > 0) ? cvector_at(vec, cvector_size(vec) - 1) : NULL) : NULL)
 
+/**
+ * @brief cvector_resize - resizes the container to contain count elements.
+ * @param vec - the vector
+ * @param count - new size of the vector
+ * @param value - the value to initialize new elements with
+ * @return void
+ */
+#define cvector_resize(vec, count, value)                          \
+    do {                                                           \
+        if (vec) {                                                 \
+            size_t cv_sz_count__ = (size_t)(count);                \
+            size_t cv_sz__       = cvector_vec_to_base(vec)->size; \
+            if (cv_sz_count__ > cv_sz__) {                         \
+                cvector_reserve((vec), cv_sz_count__);             \
+                cvector_set_size((vec), cv_sz_count__);            \
+                do {                                               \
+                    (vec)[cv_sz__++] = (value);                    \
+                } while (cv_sz__ < cv_sz_count__);                 \
+            } else {                                               \
+                while (cv_sz_count__ < cv_sz__--) {                \
+                    cvector_pop_back(vec);                         \
+                }                                                  \
+            }                                                      \
+        }                                                          \
+    } while (0)
+
 #endif /* CVECTOR_H_ */

unit-tests.c

@@ -325,6 +325,30 @@ UTEST(test, vector_shrink_to_fit) {
     cvector_free(a);
 }
 
+UTEST(test, vector_resize) {
+    cvector_vector_type(int) a = NULL;
+
+    cvector_push_back(a, 1);
+    cvector_push_back(a, 2);
+    cvector_push_back(a, 3);
+
+    cvector_resize(a, 50, 4);
+    ASSERT_EQ(cvector_size(a), (size_t)50);
+    ASSERT_EQ(a[1], 2);
+    ASSERT_EQ(a[30], 4);
+    ASSERT_EQ(a[49], 4);
+    ASSERT_EQ(a[49], 4);
+
+    cvector_resize(a, 10, 8);
+    ASSERT_EQ(cvector_size(a), (size_t)10);
+    ASSERT_EQ(a[2], 3);
+
+    cvector_resize(a, 0, 0);
+    ASSERT_EQ(cvector_size(a), (size_t)0);
+
+    cvector_free(a);
+}
+
 struct data_t {
     int num;
     int a, b, c, d;