~ chicken-core (master) 4249631a95481b547f31925832aaad9bc0b836f1

commit 4249631a95481b547f31925832aaad9bc0b836f1
Author:     Felix Winkelmann <felix.winkelmann@bevuta.com>
AuthorDate: Sun Sep 13 23:02:41 2026 +0200
Commit:     Felix Winkelmann <felix.winkelmann@bevuta.com>
CommitDate: Sun Sep 13 23:02:41 2026 +0200

    return usable value instead of 0

diff --git a/chicken.h b/chicken.h
index 2464b809..4257d3ec 100644
--- a/chicken.h
+++ b/chicken.h
@@ -1658,8 +1658,8 @@ typedef void (C_ccall *C_proc)(C_word, C_word *) C_noret;
 
 #define C_ub_i_f32vector_ref(b, i)      (((float *)C_data_pointer(C_block_item((b), 1)))[ C_unfix(i) ])
 #define C_ub_i_f64vector_ref(b, i)      (((double *)C_data_pointer(C_block_item((b), 1)))[ C_unfix(i) ])
-#define C_ub_i_f32vector_set(v, i, x)   ((((float *)C_data_pointer(C_block_item((v), 1)))[ C_unfix(i) ] = (x)), 0)
-#define C_ub_i_f64vector_set(v, i, x)   ((((double *)C_data_pointer(C_block_item((v), 1)))[ C_unfix(i) ] = (x)), 0)
+#define C_ub_i_f32vector_set(v, i, x)   ((((float *)C_data_pointer(C_block_item((v), 1)))[ C_unfix(i) ] = (x)), C_SCHEME_UNDEFINED)
+#define C_ub_i_f64vector_set(v, i, x)   ((((double *)C_data_pointer(C_block_item((v), 1)))[ C_unfix(i) ] = (x)), C_SCHEME_UNDEFINED)
 
 #define C_a_i_flonum_sin(ptr, c, x)     C_flonum(ptr, C_sin(C_flonum_magnitude(x)))
 #define C_a_i_flonum_cos(ptr, c, x)     C_flonum(ptr, C_cos(C_flonum_magnitude(x)))