atruct!

inspired by structx (that doesn't work now), atruct! macro enables to define anonymous structs like

```rs use atruct::atruct; use std::collections::HashMap;

fn main() { let anonymous = atruct!( // Type annotaion is needed for each non-literal value. // There are 2 options to annotate type: string1 @ String: String::from("string1"), // @ pattern and string2(String): String::from("string2"), // () pattern. // Their behaviors are completely the same. Use any one you like! boxoptionvec(Box>>): Box::new(Some(Vec::new())), hash @ HashMap: HashMap::from([]), vec(Vec): vec![0, 1, 0, 1, 1], nest: { a: "literals don't need type annotation", b: 100usize, // unlike v0.1, type suffix is supported for integers! }, );

println!("{}", anonymous.string1);  // string1
println!("{}", anonymous.string2);  // string2
println!("{:?}", anonymous.box_option_vec);  // Some([])
println!("{:?}", anonymous.hash);  // {}
println!("{:?}", anonymous.vec);  // [0, 1, 0, 1, 1]

} ``` ( examples/definestructofvariousvalues.rs )

atruct supports nested structs.

NOTICE: When atruct was v0.1 only literals are supported as values, BUT in v0.2 you can use (maybe) all values!

#[Return]

We usually return more than 1 values from a function. In such situations, Rust supports only tupple as a way to bundle returned values. But it's sometimes a bit anoying: when we'd like to name freely to each field, not 0, 1, 2, ...

#[Return] attribute enables such naming. You can write functions like

```rs use atruct::Return;

fn main() { let abc = get_abc(); println!("{}", abc.a); // 24 println!("{}", abc.b); // you can use any value in a field println!("{:?}", abc.c); // [-1, 0, 0, -1, 1, 0, 1, -1] }

[Return(a: u8, b: String, c: Vec)] // not supporting nest

fn getabc() { Return { a: 24, b: "you can use any value in a field".into(), c: vec![-1,0,0,-1,1,0,1,-1], } } ``` ( examples/returnstruct.rs )

Unlike atruct!, #[Return] doesn't support nested structs. So you can use returned value just like a tupple you can give any names to its fields.
#[Return] automatically generates a struct named as "FunctionName" ( e.g. if function is get_abc, for example, GetAbc ), but at the same time defines a type synonym Return. So you DON't need to memorize or write the generated struct's name.