Default Derive

Default implementation using macros

Example

Use default2::Default to set default value of each field using a macro:

```rust

[derive(default2::Default)]

struct Process { #[default(10)] id: i32, #[default("main".into())] name: String, #[default(num_cpus::get())] cpus: usize, #[default(vec![1, 2, 3])] vector: Vec, payload: u64, } ```

The following code will be generated:

```rust struct Process { id: i32, name: String, cpus: usize, payload: u64, }

impl Default for Process { fn default() -> Self { Process { id: 10, name: "main".into(), cpus: num_cpus::get(), vector: vec![1, 2, 3], payload: Default::default(), } } } ```