Fix #3 (Empty containers & IN_STR operator).

m-array.h

@@ -596,12 +596,15 @@
     M_C3(array_, name,_clean)(array);                                   \
     char c = fgetc(file);                                               \
     if (c != '[') return false;                                         \
+    c = fgetc(file);                                                    \
+    if (c == ']') return true;                                          \
+    ungetc(c, file);                                                    \
     type item;                                                          \
     M_GET_INIT oplist (item);                                           \
     do {                                                                \
       bool b = M_GET_IN_STR oplist (item, file);                        \
       c = fgetc(file);                                                  \
-      if (!b) { /* How to push back char in stream ? */ break; }        \
+      if (!b) { break; }                                                \
       M_C3(array_, name, _push_back)(array, item);                      \
     } while (c == M_GET_SEPARATOR oplist && !feof(file) && !ferror(file)); \
     M_GET_CLEAR oplist (item);                                          \