Struct Shorthand
A struct has a shorthand notation for initializing its fields. The shorthand works by passing a variable into a struct with the exact same name and type.
The following struct has a field amount with type u64.
struct Structure {
    amount: u64,
}
Using the shorthand notation we can initialize the struct in the following way.
fn call(amount: u64) {
    let structure = Structure { amount };
}
The shorthand is encouraged because it is a cleaner alternative to the following.
fn action(value: u64) {
    let amount = value;
    let structure = Structure { amount: value };
    let structure = Structure { amount: amount };
}