#include <bson/bson.h>
typedef struct _bson_value_t {


   bson_type_t value_type;


   union {


      bson_oid_t v_oid;


      int64_t v_int64;


      int32_t v_int32;


      int8_t v_int8;


      double v_double;


      bool v_bool;


      int64_t v_datetime;


      struct {


         uint32_t timestamp;


         uint32_t increment;


      } v_timestamp;


      struct {


         uint32_t len;


         char *str;


      } v_utf8;


      struct {


         uint32_t data_len;


         uint8_t *data;


      } v_doc;


      struct {


         uint32_t data_len;


         uint8_t *data;


         bson_subtype_t subtype;


      } v_binary;


      struct {


         char *regex;


         char *options;


      } v_regex;


      struct {


         char *collection;


         uint32_t collection_len;


         bson_oid_t oid;


      } v_dbpointer;


      struct {


         uint32_t code_len;


         char *code;


      } v_code;


      struct {


         uint32_t code_len;


         char *code;


         uint32_t scope_len;


         uint8_t *scope_data;


      } v_codewscope;


      struct {


         uint32_t len;


         char *symbol;


      } v_symbol;


      bson_decimal128_t v_decimal128;


   } value;
} bson_value_t;

const bson_value_t *value;
value = bson_iter_value (&iter);
if (value->value_type == BSON_TYPE_INT32) {


   printf ("%d\n", value->value.v_int32);
}