CHANGELOG

All significant changes to this project will be documented in this file.

Unreleased

Remove Exn::raise_all(parent, children). Import IteratorExt and use children.into_iter().raise(parent) instead.
Remove the unused ResultExt::Error associated type. Generic code that named it must carry the error type separately.

Let a bare Exn serve as the standard type-erased boundary. Concrete errors and typed Exn<E> values convert into it through From and ?; converting a typed exception preserves its complete frame tree and runtime error types without another allocation.
Add IteratorExt::raise to aggregate an iterator of errors or typed or type-erased exceptions beneath one typed parent.
Allow Exn<E> and marker-only adapters to use unsized root markers. Construction still requires a sized error passed by value, and conversion into arbitrary custom trait-object markers is not provided.

Exn::from_iter has been renamed to Exn::raise_all
exn::Error trait bound has been removed in favor of inlined StdError + Send + Sync + 'static bounds.
err.raise() has been moved to the exn::ErrorExt extension trait.
Exn::error(&self) has been replaced with impl Deref<Target = E> for Exn<E>.

Exn<E> now implements Deref<Target = E>, allowing for more ergonomic access to the inner error.
This crate is now no_std compatible, while the alloc crate is still required for heap allocations. It is worth noting that no_std support is a nice-to-have feature, and can be dropped if it blocks other important features in the future. Before 1.0, once exn APIs settle down, the decision on whether to keep no_std as a promise will be finalized.
Frame now implements std::error::Error.
Support convert Exn<E> into Box<dyn std::error::Error>.