+XBT_PUBLIC(void) xbt_cfg_setdefault_int(xbt_cfg_t cfg, const char *name, int val);
+XBT_PUBLIC(void) xbt_cfg_setdefault_double(xbt_cfg_t cfg, const char *name, double val);
+XBT_PUBLIC(void) xbt_cfg_setdefault_string(xbt_cfg_t cfg, const char *name, const char *val);
+XBT_PUBLIC(void) xbt_cfg_setdefault_boolean(xbt_cfg_t cfg, const char *name, const char *val);
+
+/** @brief Remove the provided value from the cell #name in #cfg. */