error: calls in constants are limited to constant functions, struct and enum constructors

> error: calls in constants are limited to constant functions, struct and enum constructors

How can I make the generated `new()` constructor *const-fn*?
E.g.:
```rust
#[derive(new, Copy, Clone)]
pub struct ColorHB {
	hue: Hue,
	#[new(value = "1.")]
	brightness: f32,
}
```