This is a crate for a more configurable derive macro to derive an
implementation for Default
. Rust's std::default
module provides a
derive implementation, but for structs, it requires that:
- Every member on the struct implement
Default
. - Every member on the struct must use the
Default
implementation.
This is fine for many cases, but consider the case of a large struct where just
one or two fields should default to something other than their type's Default
implementation: now you have to implement the whole thing.
sensible
provides a configurable derive macro that allows giving certain
fields alternate default values.
use sensible::Default;
#[derive(Default)]
struct Foo {
a: u32, // default value: 0
#[default(42)]
b: u32, // default value: 42
}