Add a forward declaration for `union un_h2o_mem_pool_chunk_t`
@@ -107,6 +107,7 @@ struct st_h2o_mem_pool_shared_entry_t {
/**
* the memory pool
*/
+union un_h2o_mem_pool_chunk_t;
typedef struct st_h2o_mem_pool_t {
union un_h2o_mem_pool_chunk_t *chunks;
size_t chunk_offset;
