[EXPERIMENTAL] Deflect brings reflection to Rust using [DWARF] debug info.
Deflect can be used to recover the concrete types of trait objects, inspect
the internal state of async generators, and pretty-print arbitrary data.
Use the [Reflect] trait to debug or recursively destructure any value.
```rust pub struct Foo { a: u8 }
// initialize the debuginfo provider let context = deflect::default_provider()?;
// create some type-erased data
let erased: Box
// cast it to &dyn Reflect
let reflectable: &dyn deflect::Reflect = &erased;
// reflect it! let value: deflect::Value = reflectable.reflect(&context)?;
// pretty-print the reflected value asserteq!(value.tostring(), "box Foo { a: 42 }");
// downcast into a BoxedDyn value
let value: deflect::value::BoxedDyn = value.try_into()?;
// dereference the boxed value let value: deflect::Value = value.deref()?;
// downcast into a Struct value
let value: deflect::value::Struct = value.try_into()?;
// get the field a by name
let Some(field) = value.field("a")? else {
panic!("no field named a!")
};
// get the value of the field let value = field.value()?;
// downcast into a u8
let value: u8 = value.try_into()?;
// check that it's equal to 42!
assert_eq!(value, 42);
``
See theexamples` directory of this crate's source for additional examples.
The current implementation of [default_provider] only works when DWARF
debuginfo is stored in the program's binary. It will not work if DWARF
debug info is split into other files. Pull requests are welcome.
This crate is highly experimental. It is not suitable as a critical
component of any system. The initial releases of this crate require
significant polish. Pull requests are welcome. Its known soundness holes
include ignorance of UnsafeCell. Don't reflect into types containing
UnsafeCell.
Additionally, the particulars of how Rust encodes DWARF debug info my change over time. This crate will do its best to keep up with those changes. Again, pull requests are welcome.
This project is licensed under the Apache License, Version 2.0, or the MIT license, at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in deflect by you, shall be licensed as MIT and Apache 2.0, without any additional terms or conditions.