Macro create_err_with_impls 

macro_rules! create_err_with_impls {
    ($(#[$meta:meta])* $vis:vis $enum_name:ident, $($variant:ident $(($type:ty))? ),* $(,)? ; $($struct_variant:ident { $($field:ident: $field_type:ty),* $(,)? } ),* $(,)?) => { ... };
}

Creates an error enum with automatic implementations of From and Display.

This macro simplifies the creation of error types by automatically implementing:

• From traits for wrapped error types, enabling use with the ? operator
• Display trait using the Debug implementation

Arguments

The macro accepts:

• Optional attributes for the enum (e.g., #[derive(Debug)])
• Visibility modifier and enum name
• List of unit variants, optionally with wrapped types
• Semicolon (;)
• List of struct variants with named fields

Example

use err_mac::create_err_with_impls;

#[derive(Debug)]
struct DatabaseError;

create_err_with_impls!(
    #[derive(Debug)]
    pub AppError,
    NotFound,
    Database(DatabaseError),
    Io(std::io::Error),
    ;
    InvalidRange { min: i32, max: i32 }
);

// The ? operator now works with wrapped error types
fn example() -> Result<(), AppError> {
    let db_result: Result<(), DatabaseError> = Ok(());
    db_result?; // Automatically converts DatabaseError to AppError
    Ok(())
}