Giftwrap

Wrap and unwrap your types the stylish way with derive macros for From/TryFrom in both directions

How does it work?

Giftwrap exposes two derive macros, Wrap and Unwrap that derive impl From<inner_type> for your_type and impl From<your_type> for inner_type (or TryFrom<your_type> in the case of enums) respectively. It works for any struct or enum variant that holds only a single type, and don't worry variants with multiple types or with types you want to convert yourself can be easily ignored with #[noWrap] and #[noUnwrap].

Examples

Consider the following error.rs ```rust pub type Result = std::result::Result;

macrorules! implfrom { ($wrapper:expr, $inner:ty) => { impl From<$inner> for Error { fn from(e: $inner) -> Error { $wrapper(e) } } }; }

[derive(Debug)]

pub enum Error { Io(std::io::Error), RppalGpio(rppal::gpio::Error), Reqwest(reqwest::Error), Qr(Box), Other(String), }

implfrom!(Error::Io, std::io::Error); implfrom!(Error::RppalGpio, rppal::gpio::Error); impl_from!(Error::Reqwest, reqwest::Error);

impl From for Error { fn from(f: qrcodegen::DataTooLong) -> Self { Error::Qr(f.into()) } }

impl From> for Error { fn from(f: Box) -> Self { Error::Qr(f) } } ``` This might seem simple enough but adding new error types is not as easy as it could be.

However with Giftwrap it's as simple as it gets: ```rust pub type Result = std::result::Result;

use giftwrap::Wrap;

[derive(Debug, Wrap)]

pub enum Error { Io(std::io::Error), RppalGpio(rppal::gpio::Error), Reqwest(reqwest::Error), #[wrapDepth(0)] Qr(), #[noWrap] Other(String), } `` Now you could add a new error variant wrapping a type from any library andGiftwrap` handles the rest for you