This crate provides a macro similar to the old try! macro, or to the ?, except it wraps the error in something else.

This is useful if you want to use a ? for easily returning say, invalid input errors, but you can't do so because you have an additional Result level for handling internal errors of a different nature.

This macro allows you to do so:

fn foo(input: Input) -> Result<Result<FinalOutput, InvalidInputError>, DatabaseError> {
    let validated_input: ValidatedInput = try_or_wrap!(validate_input_with_database(input)?, Ok);
    Ok(Ok(do_stuff_with_validated_input(validated_input)?))
}

fn validate_input_with_database(input: Input) -> Result<Result<ValidatedInput, InvalidInputError>, DatabaseError>;

try_or_wrap

This crate provides a macro similar to the old try! macro, or to the ?, except it wraps the error in something else.

This is useful if you want to use a ? for easily returning say, invalid input errors, but you can't do so because you have an additional Result level for handling internal errors of a different nature.

This macro allows you to do so:

fn foo(input: Input) -> Result<Result<FinalOutput, InvalidInputError>, DatabaseError> {
    let validated_input: ValidatedInput = try_or_wrap!(validate_input_with_database(input)?, Ok);
    Ok(Ok(do_stuff_with_validated_input(validated_input)?))
}

fn validate_input_with_database(input: Input) -> Result<Result<ValidatedInput, InvalidInputError>, DatabaseError>;