Integration of a singly linked tail queue support in C++ - c++

Question

I'm currently trying to integrate an ASN.1 decoder code written in C to the C++ Builder XE6 environment. I've encountered some problems while using the Singly linked tail queue support provided by the library, with the following call :
asn1p_wsyntx_chunk_t *wc;
while((wc = TQ_REMOVE(&(wx->chunks), next)))
asn1p_wsyntx_chunk_free(wc);
The error that I get is :
member reference type 'int' is not a pointer
The definitions of asn1p_wsyntx_chunk_t (wc) and asn1p_wsyntx_t (wx) are :
typedef struct asn1p_wsyntx_chunk_s {
enum {
WC_LITERAL,
WC_WHITESPACE,
WC_FIELD,
WC_OPTIONALGROUP
} type;
/*
* WC_LITERAL -> {token}
* WC_WHITESPACE -> {token}
* WC_FIELD -> {token}
* WC_OPTIONALGROUP -> {syntax}
*/
union {
char *token;
struct asn1p_wsyntx_s *syntax;
} content;
TQ_ENTRY(struct asn1p_wsyntx_chunk_s) next;
} asn1p_wsyntx_chunk_t;
typedef struct asn1p_wsyntx_s {
TQ_HEAD(struct asn1p_wsyntx_chunk_s) chunks;
} asn1p_wsyntx_t;
The code of the Singly linked tail is this one :
#define TQ_HEAD(type) \
struct { \
type *tq_head; \
type**tq_tail; \
}
#define TQ_MOVE(to, from) do { \
if(&(TQ_FIRST(from)) == (from)->tq_tail) { \
TQ_INIT(to); \
} else { \
(to)->tq_head = (from)->tq_head; \
(to)->tq_tail = (from)->tq_tail; \
} \
TQ_INIT(from); \
} while(0)
#define TQ_ENTRY(type) \
struct { \
type *tq_next; \
}
#define TQ_FIRST(headp) ((headp)->tq_head)
#define TQ_NEXT(el, field) ((el)->field.tq_next)
#define TQ_INIT(head) do { \
TQ_FIRST((head)) = 0; \
(head)->tq_tail = &TQ_FIRST((head)); \
} while(0)
#define TQ_FOR(var, head, field) \
for((var) = TQ_FIRST((head)); \
(var); (var) = TQ_NEXT((var), field))
/* MSVC does not have decltype(), cannot prevent side effects! */
#define TQ_ADD(head, xel, field) do { \
decltype(xel) __el = (xel); \
assert(TQ_NEXT((__el), field) == 0); \
*(head)->tq_tail = (__el); \
(head)->tq_tail = &TQ_NEXT((__el), field); \
} while(0)
#define TQ_CONCAT(head1, head2, field) do { \
if(TQ_FIRST(head2)) { \
*(head1)->tq_tail = (head2)->tq_head; \
(head1)->tq_tail = (head2)->tq_tail; \
TQ_INIT(head2); \
} \
} while(0)
/*
* Remove the first element and return it.
*/
#define TQ_REMOVE(head, field) ({ \
auto __fel = TQ_FIRST((head)); \
if(__fel == 0 \
|| (TQ_FIRST((head)) = TQ_NEXT(__fel, field)) \
== 0) { \
(head)->tq_tail = &TQ_FIRST((head)); \
} else { \
TQ_NEXT(__fel, field) = 0; \
} \
__fel; })
I've tried different casts but without success.
Thank you for your help !
EDIT :
Here is the code that I get for this call once preprocessed :
asn1p_wsyntx_chunk_t *wc;
while((wc = ({ auto __fel = (((&(wx->chunks)))->tq_head); if(__fel == 0 ||
((((&(wx->chunks)))->tq_head) = ((__fel)->next.tq_next)) == 0)
{ (&(wx->chunks))->tq_tail = &(((&(wx->chunks)))->tq_head); }
else { ((__fel)->next.tq_next) = 0; } __fel; })))
asn1p_wsyntx_chunk_free(wc);