add extern "C" guards

1 files changed, 8 insertions, 0 deletions

diff --git a/src/gc.h b/src/gc.h
index 61f8ce96a..0a4bc1c51 100644
--- a/src/gc.h
+++ b/src/gc.h
@@ -7,6 +7,10 @@
 #ifndef MRUBY_GC_H
 #define MRUBY_GC_H
 
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
 typedef struct {
   union {
     struct free_obj {
@@ -41,4 +45,8 @@ void mrb_gc_mark_ht(mrb_state*, struct RHash*);
 size_t mrb_gc_mark_ht_size(mrb_state*, struct RHash*);
 void mrb_gc_free_ht(mrb_state*, struct RHash*);
 
+#if defined(__cplusplus)
+}  /* extern "C" { */
+#endif
+
 #endif  /* MRUBY_GC_H */