Derive Macro Index

#[derive(Index)]
{
    // Attributes available to this derive:
    #[debug]
    #[index]
}

Provides an automatic Index trait implementation when-ever it’s possible.

This macro simplifies the indexing syntax of struct type.

Example Usage

Instead of manually implementing Index< T > for IsTransparent:

use core::ops::Index;

pub struct IsTransparent< T >
{
    a : Vec< T >,
}

impl< T > Index< usize > for IsTransparent< T > 
{
  type Output = T;

  #[ inline( always ) ]
  fn index( &self, index : usize ) -> &Self::Output 
  {
    &self.a[ index ]
  }
}

Use #[ index ] to automatically generate the implementation:

use derive_tools_meta::*;
 
#[ derive( Index ) ]
pub struct IsTransparent< T > 
{
 #[ index ]
  a : Vec< T >  
};