Macro stru 

macro_rules! stru {
    ($($t:tt)*) => { ... };
}

Create anonymous struct object.

Just like how an object of named struct is created, you declare a field name, followed by a colon, and then its value. Finally, you separate each field with commas.

use structz::*;

let son_age = 12;
let father = stru! {
    name: "John",
    age: son_age + 25,
};
assert_eq!(field!(father.age), 37);

When field’s value is omitted, it captures the value of the variable with the same name in the context.

use structz::*;

let name = "Smith";
let person = stru! {
    name,
    age: 30,
};
assert_eq!(field!(person.name), "Smith");