Pass block environments to pl_imp_implementationWithBlock() directly …

…instead of copying to heap

struct.c

@@ -166,26 +166,20 @@ make_struct(VALUE name, VALUE members, VALUE klass)
 	ID id = SYM2ID(RARRAY_AT(members, i));
 	if (rb_is_local_id(id) || rb_is_const_id(id)) {
 	    long j = i; /* Needed for block data reference. */
-	    VALUE
-	    (^struct_ref)(VALUE)
-	    = ^(VALUE obj)
-	    {
-		return RSTRUCT_PTR(obj)[j];
-	    };
-	    VALUE
-	    (^struct_set)(VALUE, VALUE)
-	    = ^(VALUE obj, VALUE val)
-	    {
-		VALUE *ptr = RSTRUCT_PTR(obj);
-		rb_struct_modify(obj);
-		GC_WB(&ptr[j], val);
-		return val;
-	    };
-	    rb_objc_define_method(nstr, rb_id2name(id),
-		    pl_imp_implementationWithBlock(Block_copy(struct_ref)), 0);
-	    rb_objc_define_method(nstr, rb_id2name(rb_id_attrset(id)),
-		    pl_imp_implementationWithBlock(Block_copy(struct_set)), 1);
-	}
+        /* Struct attribute reader */
+        rb_objc_define_method(nstr, rb_id2name(id),
+                pl_imp_implementationWithBlock(^(VALUE obj) {
+                    return RSTRUCT_PTR(obj)[j];
+                }), 0);
+        /* Struct attribute writer */
+        rb_objc_define_method(nstr, rb_id2name(rb_id_attrset(id)),
+                pl_imp_implementationWithBlock(^(VALUE obj, VALUE val) {
+                    VALUE *ptr = RSTRUCT_PTR(obj);
+                    rb_struct_modify(obj);
+                    GC_WB(&ptr[i], val);
+                    return val;
+                }), 1);
+	    }
     }
 
     return nstr;