garray: Add support adding literal values

GArray's g_array_append_val(), g_array_prened_val() and g_array_insert_val()
macros required an user to use literals to add a new value.

This could be inconvenient at times, but it's possible to avoid this with
recent compilers, in fact in case glib_typeof is defined we can take
advantage of it, to initialize a temporary variable to store the literal
value and pass its address to the actual function.

glib/garray.c

@@ -509,8 +509,14 @@ array_free (GRealArray     *array,
  * size automatically if necessary.
  *
  * g_array_append_val() is a macro which uses a reference to the value
- * parameter @v. This means that you cannot use it with literal values
- * such as "27". You must use variables.
+ * parameter @v.
+ * Until version 2.76 this meant that you could not use it with literal
+ * values such as `27`. You had to use variables.
+ *
+ * Starting with version 2.76, if the compiler supports the `typeof` operator
+ * you can use it with both variables and literal values.
+ * However, it may be required to use the proper suffix (such as `15L`
+ * or `55UL`) or to explicitly cast the value to the #GArray elements type.
  *
  * Returns: the #GArray
  */

glib/garray.h

@@ -32,6 +32,7 @@
 #endif
 
 #include <glib/gtypes.h>
+#include <glib/glib-typeof.h>
 
 G_BEGIN_DECLS
 
@@ -63,9 +64,35 @@ struct _GPtrArray
  * order by moving the last element to the position of the removed.
  */
 
-#define g_array_append_val(a,v)	  g_array_append_vals (a, &(v), 1)
-#define g_array_prepend_val(a,v)  g_array_prepend_vals (a, &(v), 1)
-#define g_array_insert_val(a,i,v) g_array_insert_vals (a, i, &(v), 1)
+#if defined (glib_typeof) && GLIB_VERSION_MIN_REQUIRED >= GLIB_VERSION_2_76
+  #define g_array_append_val(a, v)                   \
+    (G_GNUC_EXTENSION ({                             \
+      glib_typeof ((v)) gaa_val_ = (v);              \
+      g_array_append_vals ((a), &gaa_val_, 1);       \
+    }))
+
+  #define g_array_prepend_val(a, v)                  \
+    (G_GNUC_EXTENSION ({                             \
+      glib_typeof ((v)) gap_val_ = (v);              \
+      g_array_prepend_vals ((a), &gap_val_, 1);      \
+    }))
+
+  #define g_array_insert_val(a, i, v)                \
+    (G_GNUC_EXTENSION ({                             \
+      glib_typeof ((v)) gai_val_ = (v);              \
+      g_array_insert_vals ((a), (i), &gai_val_, 1);  \
+    }))
+#else /* !defined (glib_typeof) || GLIB_VERSION_MIN_REQUIRED < GLIB_VERSION_2_76 */
+  #define g_array_append_val(a, v)                   \
+    g_array_append_vals ((a), &((v)), 1)
+
+  #define g_array_prepend_val(a, v)                  \
+    g_array_prepend_vals ((a), &((v)), 1)
+
+  #define g_array_insert_val(a, i, v)                \
+    g_array_insert_vals ((a), (i), &((v)), 1)
+#endif
+
 #define g_array_index(a,t,i)      (((t*) (void *) (a)->data) [(i)])
 
 GLIB_AVAILABLE_IN_ALL

glib/tests/array-test.c

@@ -31,6 +31,7 @@
 #include <string.h>
 #include "glib.h"
 
+
 /* Test data to be passed to any function which calls g_array_new(), providing
  * the parameters for that call. Most #GArray tests should be repeated for all
  * possible values of #ArrayTestData. */
@@ -204,8 +205,16 @@ array_append_val (gconstpointer test_data)
   gint *segment;
 
   garray = g_array_new (config->zero_terminated, config->clear_, sizeof (gint));
-  for (i = 0; i < 10000; i++)
+  for (i = 0; i < 10000 - 1; i++)
     g_array_append_val (garray, i);
+
+#if defined (glib_typeof)
+  g_array_append_val (garray, 10000 - 1);
+#else
+  i = 10000 - 1;
+  g_array_append_val (garray, i);
+#endif
+
   assert_int_array_zero_terminated (config, garray);
 
   for (i = 0; i < 10000; i++)
@@ -218,6 +227,17 @@ array_append_val (gconstpointer test_data)
     g_assert_cmpint (segment[10000], ==, 0);
 
   g_free (segment);
+
+  garray = g_array_new (config->zero_terminated, config->clear_, sizeof (gsize));
+#if defined (glib_typeof)
+  g_array_append_val (garray, (gsize) 123);
+#else
+  i = 123;
+  g_array_append_val (garray, i);
+#endif
+
+  g_assert_cmpuint (g_array_index (garray, gsize, 0), ==, 123);
+  g_array_unref (garray);
 }
 
 /* Check that g_array_prepend_val() works correctly for various #GArray
@@ -230,8 +250,16 @@ array_prepend_val (gconstpointer test_data)
   gint i;
 
   garray = g_array_new (config->zero_terminated, config->clear_, sizeof (gint));
-  for (i = 0; i < 100; i++)
+  for (i = 0; i < 99; i++)
     g_array_prepend_val (garray, i);
+
+#if defined (glib_typeof)
+  g_array_prepend_val (garray, 99);
+#else
+  i = 99;
+  g_array_prepend_val (garray, i);
+#endif
+
   assert_int_array_zero_terminated (config, garray);
 
   for (i = 0; i < 100; i++)
@@ -302,7 +330,7 @@ array_insert_vals (gconstpointer test_data)
   const gint expected_vals2[] = { 0, 2, 3, 1 };
   const gint expected_vals3[] = { 0, 2, 3, 1, 4 };
   const gint expected_vals4[] = { 5, 0, 2, 3, 1, 4 };
-  const gint expected_vals5[] = { 5, 0, 2, 3, 1, 4, 0, 0, 0, 0, 6, 7 };
+  const gint expected_vals5[] = { 5, 0, 2, 55, 3, 1, 4, 0, 0, 0, 0, 6, 7 };
 
   /* Set up an array. */
   garray = g_array_new (config->zero_terminated, config->clear_, sizeof (gint));
@@ -344,6 +372,14 @@ array_insert_vals (gconstpointer test_data)
   assert_int_array_equal (garray, expected_vals4, G_N_ELEMENTS (expected_vals4));
   assert_int_array_zero_terminated (config, garray);
 
+  /* Insert an element in the middle */
+#if defined (glib_typeof)
+  g_array_insert_val (garray, garray->len / 2, 55);
+#else
+  i = 55;
+  g_array_insert_val (garray, garray->len / 2, i);
+#endif
+
   /* Insert some elements off the end of the array. The behaviour here depends
    * on whether the array clears entries. */
   garray_out = g_array_insert_vals (garray, garray->len + 4, vals + 6, 2);
@@ -733,7 +769,13 @@ test_array_binary_search (void)
 
   /* Testing array of size 1 */
   garray = g_array_sized_new (FALSE, FALSE, sizeof (guint), 1);
+#if defined (glib_typeof)
+  g_array_prepend_val (garray, 1u);
+#else
   i = 1;
+  g_array_prepend_val (garray, i);
+#endif
+
   g_array_append_val (garray, i);
 
   g_assert_true (g_array_binary_search (garray, &i, cmpint, NULL));