From 3ff695d815a2d8a20d9eb238800be414d2881ab0 Mon Sep 17 00:00:00 2001
From: timofey <tim@ongoteam.yaconnect.com>
Date: Thu, 1 Jun 2023 12:18:08 +0000
Subject: [PATCH] `futures::join`

---
 src/ch04/s00-concerns.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/ch04/s00-concerns.md b/src/ch04/s00-concerns.md
index fc56360..2c3c367 100644
--- a/src/ch04/s00-concerns.md
+++ b/src/ch04/s00-concerns.md
@@ -15,4 +15,7 @@ See the [relevant subchapter](./s04-covariance.md)
 ## `Fail`/`FailMonad`/etc. have unclear semantics
 See the [relevant subchapter](./s05-fail.md)
 
+## Is `FutureInstance` actually feasible?
+Todo: measure `futures::join` performance.
+
 ## Can `WeakFunctor` be an associated type of a `Functor` instead of its supertype?