Avoid clippy::let-underscore-drop

[cschramm]

Description

The following main.rs replicates the clippy warning:

use yew::prelude::*;

struct Props {
    droppable: Vec<()>,
}

fn component(props: &Props) -> Html {
    let props = Props { droppable: Vec::new() };
    html! { <Component ..props /> }
}

fn main() {}

If I'm not mistaken this happens when using the .. on any Properties with a field that implements Drop.

Checklist

• I have reviewed my own code
• I have added tests

[WorldSEnder]

Correct me if I'm wrong: Is this because clippy thinks let _ = #props_ident.#label; moves the field out of the prop struct - even though the method is never called?

If my assumption is correct, then perhaps instead of working around the mechanism by which clippy lints this (binding to _some_name instead of _), we could also use let _ = &#props_ident.#label; to avoid the move?

[cschramm]

Yes, you're right. That works just as well. 👌

[github-actions]

Visit the preview URL for this PR (updated for commit 80f3a44):

https://yew-rs-api--pr2952-let-underscore-drop-g54b08uq.web.app

_{(expires Tue, 15 Nov 2022 15:13:56 GMT)}

_{🔥 via Firebase Hosting GitHub Action 🌎}

[github-actions]

Benchmark - SSR

Yew Master

Benchmark	Round	Min (ms)	Max (ms)	Mean (ms)	Standard Deviation
Baseline	10	357.538	410.253	375.299	16.923
Hello World	10	679.746	726.237	697.269	15.739
Function Router	10	2509.595	2751.933	2602.691	70.480
Concurrent Task	10	1009.518	1011.140	1010.194	0.567

Pull Request

Benchmark	Round	Min (ms)	Max (ms)	Mean (ms)	Standard Deviation
Baseline	10	353.273	392.905	366.720	13.427
Hello World	10	671.954	718.539	689.391	15.807
Function Router	10	2539.653	2636.505	2589.640	27.559
Concurrent Task	10	1008.583	1012.370	1009.908	1.072

[github-actions]

Size Comparison

examples	master (KB)	pull request (KB)	diff (KB)	diff (%)
async_clock	106.161	106.159	-0.002	-0.002%
boids	170.390	170.396	+0.006	+0.003%
communication_child_to_parent	90.032	90.030	-0.002	-0.002%
communication_grandchild_with_grandparent	104.881	104.880	-0.001	-0.001%
communication_grandparent_to_grandchild	100.746	100.742	-0.004	-0.004%
communication_parent_to_child	87.133	87.134	+0.001	+0.001%
contexts	107.362	107.354	-0.009	-0.008%
counter	85.049	85.050	+0.001	+0.001%
counter_functional	85.522	85.523	+0.001	+0.001%
dyn_create_destroy_apps	87.910	87.913	+0.003	+0.003%
file_upload	99.644	99.644	0	0.000%
function_memory_game	162.890	162.881	-0.009	-0.005%
function_router	347.179	347.186	+0.007	+0.002%
function_todomvc	157.651	157.645	-0.007	-0.004%
futures	221.941	221.942	+0.001	+0.000%
game_of_life	104.576	104.577	+0.001	+0.001%
immutable	180.987	180.974	-0.014	-0.008%
inner_html	81.910	81.911	+0.001	+0.001%
js_callback	110.881	110.882	+0.001	+0.001%
keyed_list	195.522	195.523	+0.001	+0.000%
mount_point	84.659	84.658	-0.001	-0.001%
nested_list	111.618	111.620	+0.002	+0.002%
node_refs	92.535	92.536	+0.001	+0.001%
password_strength	1546.184	1546.181	-0.003	-0.000%
portals	95.951	95.949	-0.002	-0.002%
router	316.991	316.996	+0.005	+0.002%
simple_ssr	151.584	151.582	-0.002	-0.001%
ssr_router	392.271	392.273	+0.003	+0.001%
suspense	108.703	108.697	-0.006	-0.005%
timer	87.941	87.939	-0.002	-0.002%
todomvc	138.959	138.962	+0.003	+0.002%
two_apps	85.714	85.713	-0.001	-0.001%
web_worker_fib	152.038	152.037	-0.001	-0.001%
webgl	84.352	84.351	-0.001	-0.001%

✅ None of the examples has changed their size significantly.

[hamza1311]

Looks good