Derive Macro futures_signals_structs::AsMutableStruct

#[derive(AsMutableStruct)]
{
    // Attributes available to this derive:
    #[MutableStructName]
}

Derives a function called as_mutable_struct() that returns a version of the struct where all fields are Mutable objects.

    #[derive(AsMutableStruct)]
    struct PlayerScore {
        hits: u32,
        multiplier: f32,
    }
 
    fn main() {
        let score = PlayerScore {
            hits: 4,
            multiplier: 0.4,
        };
        let mutable_score = score.as_mutable_struct();
        mutable_score.hits.set(6);
        mutable_score.multiplier.set(0.5);
    }

By default this creates a new struct called MutablePlayerScore that can also be constructed directly as necessary.

    let mutable_score = MutablePlayerScore {
        hits: Mutable::new(5),
        multiplier: Mutable::new(1.4),
    };

Either way you construct it, the mutable object can be 'snapshotted' into the original struct.

    assert_eq!(mutable_score.snapshot(), PlayerScore {
        hits: 5,
        multiplier: 1.4,
    });

The mutable value can also be updated to match a new static struct.

    mutable_score.update(PlayerScore {
        hits: 50,
        multiplier: 15,
    });
    assert_eq!(mutable_score.snapshot(), PlayerScore {
        hits: 50,
        multiplier: 15,
    });

Structs can depend on other structs when annotated with #[mutable_type]

    #[derive(AsMutableStruct)]
    struct GameScore {
        #[mutable_type = "MutablePlayerScore"] player_1: PlayerScore,
        #[mutable_type = "MutablePlayerScore"] player_2: PlayerScore,
    }