-// ========== SD Layer ==============
-typedef struct SD_workstation *SD_workstation_priv_t;
-SD_workstation_priv_t sg_host_sd(sg_host_t host);
-XBT_PUBLIC(void) sg_host_sd_set(sg_host_t host, SD_workstation_priv_t priv);
-XBT_PUBLIC(void) sg_host_sd_destroy(sg_host_t host);
-
-// ========== Simix layer =============
-typedef struct s_smx_host_priv *smx_host_priv_t;
-XBT_PUBLIC(smx_host_priv_t) sg_host_simix(sg_host_t host);
-XBT_PUBLIC(void) sg_host_simix_set(sg_host_t host, smx_host_priv_t priv);
-XBT_PUBLIC(void) sg_host_simix_destroy(sg_host_t host);