Module macros 

Error handling macros for context creation Ergonomic macros for creating lazy or structured ErrorContext.

These macros provide convenient shortcuts for attaching rich metadata to errors:

• crate::rail - Wraps a Result-producing block and converts it into a BoxedComposableResult via ErrorPipeline::finish.
• crate::context - Defers formatting until the context is consumed, avoiding unnecessary allocations on the success path.
• crate::location - Automatically captures the current file path and line number using file!() and line!().
• crate::tag - Attaches a short categorical label for filtering and searching.
• crate::metadata - Adds arbitrary key-value pairs for structured logging.

Examples

use error_rail::{context, location, rail, tag, metadata, ErrorPipeline};

let result: Result<(), &str> = Err("failed");
let pipeline = ErrorPipeline::new(result)
    .with_context(context!("user_id: {}", 123))
    .with_context(location!())
    .with_context(tag!("auth"))
    .with_context(metadata!("retry_count", "3"))
    .finish();

// Equivalent rail! shorthand that also returns a boxed composable result
let _ = rail!({
    Err::<(), &str>("failed")
        .map_err(|err| err)
});