clippy::manual_string_new: empty String is being created manually

What you see

warning: empty String is being created manually
 --> main.rs:3:9
  |
3 | let a = "".to_string();
  |         ^^^^^^^^^^^^^^ help: consider using: `String::new()`
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/stable/index.html#manual_string_new
  = note: `-W clippy::manual-string-new` implied by `-W clippy::pedantic`

Real output of Clippy 0.1.99 (Rust 1.99) on the example below. Names and line numbers in yours will differ.

Does it matter?

Different ways of creating an empty string makes your code less standardized, which can be confusing.

Stricter lints with some false positives. Off by default; opt in with clippy::pedantic.

How to fix it

Clippy can fix this one for you: run cargo clippy --fix (add --allow-dirty if you have uncommitted changes). Review the diff before you commit.

Flagged

let a = "".to_string();
let b: String = "".into();

Write this instead

let a = String::new();
let b = String::new();

Turn it off, or on

It is off by default. To use it, set it to warn or deny:

[lints.clippy]
manual_string_new = "warn"

#![warn(clippy::manual_string_new)]

cargo clippy -- -W clippy::manual-string-new

The [lints] table needs Rust 1.74 or newer. In a workspace, put it under [workspace.lints.clippy] and add [lints] workspace = true to each member.