# Objective
- Implementing `Default` for
[`CubicCurve`](https://docs.rs/bevy/latest/bevy/math/cubic_splines/struct.CubicCurve.html)
does not make sense because it cannot be mutated after creation.
- Closes#11209.
- Alternative to #11211.
## Solution
- Remove `Default` from `CubicCurve`'s derive statement.
Based off of @mockersf comment
(https://github.com/bevyengine/bevy/pull/11211#issuecomment-1880088036):
> CubicCurve can't be updated once created... I would prefer to remove
the Default impl as it doesn't make sense
---
## Changelog
- Removed the `Default` implementation for `CubicCurve`.
## Migration Guide
- Remove `CubicCurve` from any structs that implement `Default`.
- Wrap `CubicCurve` in a new type and provide your own default.
```rust
#[derive(Deref)]
struct MyCubicCurve<P: Point>(pub CubicCurve<P>);
impl Default for MyCubicCurve<Vec2> {
fn default() -> Self {
let points = [[
vec2(-1.0, -20.0),
vec2(3.0, 2.0),
vec2(5.0, 3.0),
vec2(9.0, 8.0),
]];
Self(CubicBezier::new(points).to_curve())
}
}
```