Borrowcheck woes

errors

test3.rs:106:63: 106:71 error: lifetime of `comp_set` is too short to guarantee its contents can be safely reborrowed
test3.rs:106            self.get_comp_idx(Component::get_type(None::<T>)).map(|idx| comp_set.get_mut(idx))
                                                                                    ^~~~~~~~
test3.rs:105:2: 115:3 note: `comp_set` would have to be valid for the lifetime &'l  as defined on the block at 105:1...
test3.rs:105    {
test3.rs:106            self.get_comp_idx(Component::get_type(None::<T>)).map(|idx| comp_set.get_mut(idx))
test3.rs:107 
test3.rs:108            /*
test3.rs:109            match self.get_comp_idx(Component::get_type(None::<T>))
test3.rs:110            {
             ...
test3.rs:106:3: 106:85 note: ...but `comp_set` is only valid for the method call at 106:2
test3.rs:106            self.get_comp_idx(Component::get_type(None::<T>)).map(|idx| comp_set.get_mut(idx))
                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
error: aborting due to previous error

test.rs

// The ComponentSet get_mut looks like this
fn get_mut<'l>(&'l mut self, comp_idx: uint) -> &'l mut T {}

fn get_mut<'l, T: Component>(&self, comp_set: &'l mut ComponentSet<T>) -> Option<&'l mut T>
{
	self.get_comp_idx(Component::get_type(None::<T>)).map(|idx| comp_set.get_mut(idx))
	
	/*
	match self.get_comp_idx(Component::get_type(None::<T>))
	{
		Some(idx) => Some(comp_set.get_mut(idx)),
		None => None
	}
	*/
}