Rust structs, sometimes called structures, resemble struct types in C and C++, classes in Python, and objects in JavaScript.

A struct assembles several values of assorted types together into a single value so you can deal with them as a unit. Given a struct, you can read and modify its individual components. And a struct can have methods associated with it that operate on its components.

→ struct는 다양한 타입의, 여러 value들을 하나의 value로 조합해서, 하나의 단위로 다룰 수 있게 함!

→ struct가 주어지면, individual components를 읽고, 수정할 수 O

• struct는 그 components에 대해서 작동하는 것과 관련된 methods를 가질 수 있음

Rust has three kinds of struct types, named-field, tuple-like, and unit-like, which differ in how you refer to their components: a named-field struct gives a name to each component, whereas a tuple-like struct identifies them by the order in which they appear. Unit-like structs have no components at all; these are not common, but more useful than you might think.

Named Field Structs

The definition of a named0field struct type looks like this:

/// A rectangle of eight-bit grayscale pixels.
struct GrayscaleMap { 
	pixels: Vec<u8>, 
	size: (usize, usize)
}

This declares a type GrayscaleMap with two fields named pixels and size, of the given types.

→ pixels와 size라는 이름을 가진 두 개의 field와 함께 GrayscaleMap이라는 type을 정의하고 있음.

The convention in Rust is for all types, structs included, to have names that capitalize the first letter of each word, like GrayscaleMap, a convention called CamelCase (or PascalCase). Fields and methods are lowercase, with words separated by underscores. This is called snake_case.

→ Rust의 관습에 따르면 모든 type들의 이름은 각 단어의 첫 번째 문자가 대문자여야 하고, Fields와 methods들의 이름은 모든 문자들이 소문자이며, 각 단어들은 underscore로 분리되어야 한다.

You can construct a value of this type with a struct expression, like this:

let width = 1024;
let height = 576;
let image = GrayscaleMap {
		pixels: vec![0; width * height],
    size: (width, height)
    };

A struct expression starts with the type name (GrayscaleMap) and lists the name and value of each field using key:value syntax, all enclosed in curly braces.

There’s also shorthand for populating fields from local variables or arguments with the same name: