Clippy lints / Style
Clippy lint · Style · checked with Clippy 0.1.99
clippy::needless_doctest_main: Checks for fn main() {
What it meansChecks for fn main() { .. } in doctests It is in the style group and warns by default.
Does it matter?
The test can be shorter (and likely more readable) if the fn main() is left implicit.
Code that works but is not idiomatic Rust. Warns by default.
How to fix it
Clippy does not fix this one automatically. Change the code by hand:
Flagged
/// An example of a doctest with a `main()` function
///
/// # Examples
///
/// ```
/// fn main() {
/// // this needs not be in an `fn`
/// }
/// ```
fn needless_main() {
unimplemented!();
}
Turn it off, or on
Allow it where it does not fit your code, as narrowly as you can:
On one item
#[allow(clippy::needless_doctest_main)]
fn my_function() { /* ... */ }Whole crate (Cargo.toml)
[lints.clippy]
needless_doctest_main = "allow"One run
cargo clippy -- -A clippy::needless-doctest-mainThe [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.
Clippy's own documentation
What it does
Checks for fn main() { .. } in doctests
Why is this bad?
The test can be shorter (and likely more readable)
if the fn main() is left implicit.
Examples
/// An example of a doctest with a `main()` function
///
/// # Examples
///
/// ```
/// fn main() {
/// // this needs not be in an `fn`
/// }
/// ```
fn needless_main() {
unimplemented!();
}
From the Clippy lint list (0.1.99), part of the Rust project, MIT or Apache-2.0. Official entry.
Related lints
- needless_returnunneeded `return` statement
- new_without_defaultChecks for public types with a pub fn new() -> Self method and no implementation of Default
- len_zeroChecks for getting the length of something via .len() just to compare to zero, and suggests using .is_empty() where applicable
- mut_mutex_lockcalling `&mut Mutex::lock` unnecessarily locks an exclusive (mutable) reference
- needless_borrowthis expression creates a reference which is immediately dereferenced by the compiler
- needless_borrows_for_generic_argsthe borrowed expression implements the required traits
- needless_elsethis `else` branch is empty
- needless_late_initunneeded late initialization
- needless_parens_on_range_literalsneedless parenthesis on range literals can be removed
All 847 Clippy lints · Rust compiler errors · Cargo.toml checker
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Related lintclippy::needless_returnunneeded `return` statementRead it next →Did this answer your question?