failed to resolve: use of undeclared crate or module futures_util

[fate-zx]

code:

use std::future::{ready, Ready};

use actix_web::{
    dev::{forward_ready, Service, ServiceRequest, ServiceResponse, Transform},
    Error,
};
use futures_util::future::LocalBoxFuture;

// There are two steps in middleware processing.
// 1. Middleware initialization, middleware factory gets called with
//    next service in chain as parameter.
// 2. Middleware's call method gets called with normal request.
pub struct SayHi;
`

warn:
error[E0433]: failed to resolve: use of undeclared crate or module `futures_util`
 --> src\middleware\auth_middleware.rs:7:5
  |
7 | use futures_util::future::LocalBoxFuture;
  |     ^^^^^^^^^^^^ use of undeclared crate or module `futures_util`

[robjtede]

in your Cargo.toml, add:

futures-util = "0.3"