Function sequence 

pub fn sequence(from: u16, n: u16) -> u16

Returns a consecutive term. from is the first term.

Usage

use chrono::{NaiveDate, NaiveDateTime};
use serde::{Deserialize, Serialize};

#[derive(Serialize, Deserialize)]
struct Post {
    id: u16,
    title: String,
    approved: bool,
    created_at: NaiveDateTime,
}

beaver::define! {
    PostFactory (Post) {
        id -> |n| n,
        // First post's title: "post-100"
        // Second post's title: "post-101"
        title -> |n| format!("post-{}", beaver::sequence(100, n)),
        approved -> |_| false,
        created_at -> |_| NaiveDate::from_ymd(2020, 1, 1).and_hms(0, 0, 0),
    }
}