Recommend <collection type>::from

What it does

I discovered HashMap::from a bit late, and wish clippy had encouraged me to use this helpful constructor function rather than the collect-based boilerplate I have been using so far. I think I was cribbing some of my Rust knowledge from older tutorials.

Advantage

Discourages unnecessary boilerplate

Reduces mistakes

Encourages higher quality code

Drawbacks

No response

Example

let m = HashMap<String, String> = vec![
        ("bsdmakefile", "bmake"),
        ("gnumakefile", "gmake"),
        ("makefile", "make"),
    ]
    .into_iter()
    .map(|(k, v)| (k.to_string(), v.to_string()))
    .collect::<HashMap<String, String>>();

Could be written as:

let m = HashMap<String, String>from([
        ("bsdmakefile", "bmake"),
        ("gnumakefile", "gmake"),
        ("makefile", "make"),
    ];

No implementation files, tests, or entry points are named. Start by reviewing the proposed collect-based example and the requested HashMap::from recommendation; done means Clippy identifies the applicable boilerplate and suggests the collection constructor without changing unrelated code.