Macro implementations of `#[derive(FromValue, IntoValue)]`.
As this crate is a [`proc_macro`] crate, it is only allowed to export
[procedural macros](https://doc.rust-lang.org/reference/procedural-macros.html).
Therefore, it only exports [`IntoValue`] and [`FromValue`].
To get documentation for other functions and types used in this crate, run
`cargo doc -p nu-derive-value --document-private-items`.
This crate uses a lot of
[`proc_macro2::TokenStream`](https://docs.rs/proc-macro2/1.0.24/proc_macro2/struct.TokenStream.html)
as `TokenStream2` to allow testing the behavior of the macros directly, including the output
token stream or if the macro errors as expected.
The tests for functionality can be found in `nu_protocol::value::test_derive`.
This documentation is often less reference-heavy than typical Rust documentation.
This is because this crate is a dependency for `nu_protocol`, and linking to it would create a
cyclic dependency.
Also all examples in the documentation aren't tested as this crate cannot be compiled as a
normal library very easily.
This might change in the future if cargo allows building a proc-macro crate differently for
`cfg(doctest)` as they are already doing for `cfg(test)`.
The generated code from the derive macros tries to be as
[hygienic](https://doc.rust-lang.org/reference/macros-by-example.html#hygiene) as possible.
This ensures that the macro can be called anywhere without requiring specific imports.
This results in obtuse code, which isn't recommended for manual, handwritten Rust
but ensures that no other code may influence this generated code or vice versa.