Trait derive_merge_struct::Merge

pub trait Merge {
    // Required method
    fn merge(&mut self, another: Self);
}

The trait is designed for named struct. Can be used to partially update configuration.

• If the field of struct has attribute #[exclude], this.field remain the same.
• ElIf the field of struct is not Option: this.field = that.field.clone()
• ElIf the field of struct has attribute #[force]: this.field = that.field.clone()
• ElIf the field of struct is Option and doesn’t have attribute #[force]:
  • If that.field.is_some(): this.field = that.field.clone()
  • If that.field.is_none(): this.field remain the same.

Example

use derive_merge_struct::Merge;
#[derive(Merge)]
#[exclude]
struct TestStruct {
    a: Option<i32>,
    b: Option<String>,
    c: Option<u32>,
    #[force]
    d: Option<i32>,
    #[exclude]
    e: Option<i32>,
    f: i32
}
let mut this = TestStruct {
    a: Some(1),
    b: None,
    c: Some(1),
    d: Some(1),
    e: None,
    f: 1
};
let that = TestStruct {
    a: Some(2),
    b: Some("hello".to_string()),
    c: None,
    d: None,
    e: Some(1),
    f: 2
};
this.merge(that);
assert_eq!(this.a, Some(2));
assert_eq!(this.b, Some("hello".to_string()));
assert_eq!(this.c, Some(1));
assert_eq!(this.d, None);
assert_eq!(this.e, None);
assert_eq!(this.f, 2);

Required Methods

fn merge(&mut self, another: Self)

Object Safety

This trait is not object safe.

Implementors