1 files changed, 11 insertions, 0 deletions
diff --git a/string.c b/string.c
index c9621d399d..7f107c26ad 100644
--- a/string.c
+++ b/string.c
@@ -758,6 +758,17 @@ rb_str_free(VALUE str)
     }
 }
 
+size_t
+rb_str_memsize(VALUE str)
+{
+    if (!STR_EMBED_P(str) && !STR_SHARED_P(str)) {
+	return RSTRING(str)->as.heap.aux.capa;
+    }
+    else {
+	return 0;
+    }
+}
+
 VALUE
 rb_str_to_str(VALUE str)
 {