Only define instance constants if struct name is non-local

This allows defining structs whose name contains a dot.

Author: ISSOtm

README.md

@@ -151,7 +151,7 @@ Of particular interest is `DEF STRUCT_SEPARATOR equs "."`, which causes members
 
 It is unnecessary to put a label right before `dstruct`, since a label is declared at the struct's root.
 
-Two extra constants are declared, that mirror the struct's: `sizeof_Player` would be equal to `sizeof_NPC`, and `Player_nb_fields` would equal `NPC_nb_fields` (sse below).
+Unless the struct's name contains a dot `.`, two extra constants are declared, that mirror the struct's: `sizeof_Player` would be equal to `sizeof_NPC`, and `Player_nb_fields` would equal `NPC_nb_fields` (sse below).
 These constants will keep their values even if the originals, such as `sizeof_NPC`, are `PURGE`'d.
 Like structs' constants, these are not exported unless `STRUCTS_EXPORT_CONSTANTS` is defined.
 

structs.inc

@@ -308,12 +308,14 @@ MACRO dstruct ; struct_type, instance_name[, ...]
         PURGE FIELD_ID, ARG_NUM, DSTRUCT_SEPARATOR
 
         ; Define instance's properties from struct's
-        DEF \2_nb_fields EQU \1_nb_fields
-        DEF sizeof_\2    EQU @ - (\2)
-        structs_assert sizeof_\1 == sizeof_\2
+        IF !STRIN("\2", ".")
+            DEF \2_nb_fields EQU \1_nb_fields
+            DEF sizeof_\2    EQU @ - (\2)
+            structs_assert sizeof_\1 == sizeof_\2
 
-        IF DEF(STRUCTS_EXPORT_CONSTANTS)
-            EXPORT \2_nb_fields, sizeof_\2
+            IF DEF(STRUCTS_EXPORT_CONSTANTS)
+                EXPORT \2_nb_fields, sizeof_\2
+            ENDC
         ENDC
 
         PURGE IS_NAMED_INSTANTIATION