From f8b4f4410586ab0274d142a68758078c692c7025 Mon Sep 17 00:00:00 2001
From: Patrick Pelissier <patrick.pelissier@gmail.com>
Date: Sun, 15 Aug 2021 21:44:36 +0200
Subject: [PATCH] Add ARRAY_INIT_VALUE

---
 README.md           | 14 ++++++++++++++
 m-array.h           |  6 ++++++
 tests/test-marray.c |  7 +++++++
 3 files changed, 27 insertions(+)

diff --git a/README.md b/README.md
index 1ab8fc95..7c34250a 100644
--- a/README.md
+++ b/README.md
@@ -1479,6 +1479,20 @@ are provided.
 Return the oplist of the array defined by calling ARRAY\_DEF with name & oplist. 
 If there is no given oplist, the default oplist for standard C type is used.
 
+#### ARRAY\_INIT\_VALUE()
+
+Define an initial value that is suitable to initialize global variable(s)
+of the type associated to the (array) oplist 'oplist'.
+It enables to create an array as a global variable and to initialize it.
+
+The array should still be cleared manually to avoid leaking memory.
+
+Example:
+
+        ARRAY_DEF(array_int_t, int)
+        array_int_t my_array = ARRAY_INIT_VALUE();
+
+
 #### Created methods
 
 In the following methods, name stands for the name given to the macro.
diff --git a/m-array.h b/m-array.h
index bfaf4e1e..d895ed6e 100644
--- a/m-array.h
+++ b/m-array.h
@@ -53,6 +53,12 @@
                     (__VA_ARGS__ )))
 
 
+/* Define an init value to init global variables of type array.
+  USAGE:
+    array_t global_variable = ARRAY_INIT_VALUE(array_oplist);
+ */
+#define ARRAY_INIT_VALUE()                                                    \
+  { { 0, 0, NULL } }
 
 /********************************************************************************/
 /********************************** INTERNAL ************************************/
diff --git a/tests/test-marray.c b/tests/test-marray.c
index 768eb454..e7fb3c18 100644
--- a/tests/test-marray.c
+++ b/tests/test-marray.c
@@ -41,6 +41,8 @@ ARRAY_DEF(array_ulong, uint64_t)
 ARRAY_DEF_AS(array_double, ArrayDouble, ArrayDoubleIt, double)
 #define M_OPL_ArrayDouble() ARRAY_OPLIST(array_double, M_DEFAULT_OPLIST)
 
+ArrayDouble g_array = ARRAY_INIT_VALUE();
+
 static void test_uint(void)
 {
   array_uint_t v;
@@ -362,6 +364,11 @@ static void test_double(void)
       ref += 1.0;
     }
   }
+
+  assert( array_double_empty_p(g_array));
+  array_double_push_back(g_array, 34.);
+  assert( array_double_size(g_array) == 1);
+  array_double_clear(g_array);
 }
 
 int main(void)