Macro structural::make_struct

macro_rules! make_struct {
    (
        $( #![$inner_attrs:meta] )*
        $(
            $( #[$field_attrs:meta] )*
            $field_name:ident : $field_value:expr,
        )*
    ) => { ... };
}

Constructs an anonymous struct, which implements the IntoFieldMut accessor trait for all its field.

Syntax

Here is the entire syntax for this macro:

make_struct!{
    // This is an inner attribute,which is applied to the struct declaration.
    // In this case it's deriving `Debug` for the struct.
    #![derive(Debug)]
     
    // This is an attribute on the first field.
    #[doc="you must put attributes for the first field after the inner attributes"]
    size_cm:0,
    place:"Anctartica",
}

Example

use structural::{GetFieldExt,make_struct,structural_alias,ti};

use std::fmt::Debug;

structural_alias!{
    pub trait Runner{
        mut move name:String,
        mut move stamina:u32,
    }
}

// Everything bellow could be on a separate crate (ignoring imports)


fn get_runner(this:&(impl Runner+Debug) ){
    assert_eq!( this.field_(ti!(name)).as_str(), "hello","{:?}",this);
    assert_eq!( this.field_(ti!(stamina)), &100,"{:?}",this);
}

get_runner(&make_struct!{
    #![derive(Debug)]
    name:"hello".into(),
    stamina:100,
});

// Unfortunately,due to a rustc bug as of 2019-11-02,
// you can't call the accessor methods provided by GetFieldExt
// on the return value of this function.
// Issue for the rustc bug: https://github.com/rust-lang/rust/issues/66057
// fn get_runner()->impl Runner+Copy+Clone{
//     make_struct!{
//         #![derive(Copy,Clone)]
//         name:"hello".into(),
//         stamina:4_000_000_000,
//     }
// }


fn get_dyn_runner()->Box<dyn Runner>{
    Box::new(make_struct!{
       name:"hello".into(),
       stamina:4_000_000_000,
    })
}

{
    let runner=get_dyn_runner();
    assert_eq!( runner.field_(ti!(name)).as_str(), "hello" );
    assert_eq!( runner.field_(ti!(stamina)), &4_000_000_000 );
}