union の deconst 外すやつ

deconst.patch

diff --git a/iseq.c b/iseq.c
index 997dd7f1f7..be9efb9aad 100644
--- a/iseq.c
+++ b/iseq.c
@@ -989,11 +989,8 @@ static const rb_data_type_t iseqw_data_type = {
 static VALUE
 iseqw_new(const rb_iseq_t *iseq)
 {
-    union { const rb_iseq_t *in; void *out; } deconst;
     VALUE obj;
-
-    deconst.in = iseq;
-    obj = TypedData_Wrap_Struct(rb_cISeq, &iseqw_data_type, deconst.out);
+    obj = TypedData_Wrap_Struct(rb_cISeq, &iseqw_data_type, (void *)iseq);
     RB_OBJ_WRITTEN(obj, Qundef, iseq);
 
     return obj;

foo.c

int bar(void* b) {
    return 1;
}
void tekitou(char* a)
{
    bar((void *)a);
}

int main(int argc, char const* argv[])
{
    tekitou("aiueo");
    return 0;
}

sh

$ clang -Wcast-qual  foo.c -o foo