Static rustc_lint::builtin::ANONYMOUS_PARAMETERS
source · pub static ANONYMOUS_PARAMETERS: &Lint
Expand description
The anonymous_parameters
lint detects anonymous parameters in trait
definitions.
Example
ⓘ
#![deny(anonymous_parameters)]
// edition 2015
pub trait Foo {
fn foo(usize);
}
fn main() {}
{{produces}}
Explanation
This syntax is mostly a historical accident, and can be worked around
quite easily by adding an _
pattern or a descriptive identifier:
trait Foo {
fn foo(_: usize);
}
This syntax is now a hard error in the 2018 edition. In the 2015
edition, this lint is “warn” by default. This lint
enables the cargo fix
tool with the --edition
flag to
automatically transition old code from the 2015 edition to 2018. The
tool will run this lint and automatically apply the
suggested fix from the compiler (which is to add _
to each
parameter). This provides a completely automated way to update old
code for a new edition. See issue #41686 for more details.