Macro rutie::unsafe_methods

macro_rules! unsafe_methods {
    ($rtself_class : ty, $rtself_name : ident,
 $(fn $method_name : ident($($arg_name : ident : $arg_type : ty), *) ->
   $return_type : ty $body : block $(,) ?) *) => { ... };
}

Creates unsafe callbacks for Ruby methods

This macro is unsafe, because:

• it uses automatic unsafe conversions for arguments (no guarantee that Ruby objects match the types which you expect);
• no bound checks for the array of provided arguments (no guarantee that all the expected arguments are provided);

That is why creating callbacks in unsafe way may cause panics.

Due to the same reasons unsafe callbacks are faster.

Use it when:

• you own the Ruby code which passes arguments to callback;
• you are sure that all the object has correct type;
• you are sure that all the required arguments are provided;
• Ruby code has a good test coverage.

Examples

#[macro_use]
extern crate rutie;

use rutie::{Boolean, Class, Fixnum, Object, RString, VM};

// Creates `string_length_equals` functions
unsafe_methods!(
    RString, // type of `self` object
    rtself, // name of `self` object which will be used in methods

    fn string_length_equals(expected_length: Fixnum) -> Boolean {
        let real_length = rtself.to_str().len() as i64;

        Boolean::new(expected_length.to_i64() == real_length)
    }
);

fn main() {
    Class::from_existing("String").define(|klass| {
        klass.def("length_equals?", string_length_equals);
    });
}

Ruby:

class String
  def blank?
  end

  def length_equals?(expected_length)
  end
end