An unwrap! macro for Rust.

The crate provides a macro, unwrap! which can be used to unwrap values of type Result or Option (or any type that implements VerboseUnwrap). The advantage of using this macro over the .unwrap() methods is that, on a panic, it will print the file name, line number, column number, and function name of where the macro was called from.

Example

This code:

let x: Result<(), u32> = Err(123);
let y = unwrap!(x);

Panics with the following message:

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!   unwrap! called on Result::Err                                              !
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
example.rs:2,9 in example_module::example_function

Err(
    123
)

unwrap! can also be called with an extra error message as an optional second argument.

let x: Option<()> = None;
let y = unwrap!(x, "Oh no!");

Prints:

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!   unwrap! called on Option::None                                             !
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
example.rs:2,9 in example_module::example_function
Oh no!