Attribute Macro custom_try 

#[custom_try]

Replace expr? occurrences in the decorated item with r#try!( expr ).

The r#try! default path can be overridden by giving it as an argument to the attribute macro:

Examples

1. For FFI

• use ::custom_try::custom_try;
  
  #[repr(transparent)]
  pub struct FfiResult {
      pub status_code: ::std::os::raw::c_int,
  }
  
  impl FfiResult {
      pub const OK: Self = Self { status_code: 0 };
      pub const ERR: Self = Self { status_code: -1 };
  }
  
  macro_rules! unwrap_option {( $option:expr $(,)? ) => (
      match $option {
          Some(thing) => thing,
          None => return $crate::FfiResult::ERR,
      }
  )}
  
  #[custom_try(unwrap_option!)]
  extern "C" fn ffi_function() -> FfiResult {
      let x = the_answer_to_life_the_universe_and_everything()?;
      println!("{}", x);
      FfiResult::OK
  }
  
  /// If you only have one case of `?` semantics, you can default to that one
  /// using the default `r#try!` macro name.
  use unwrap_option as r#try;
  
  #[custom_try]
  extern "C" fn ffi_function2() -> FfiResult {
      let x = the_answer_to_life_the_universe_and_everything()?;
      println!("{}", x);
      FfiResult::OK
  }