Macro lens_rs::optics

optics!() { /* proc-macro */ }

macro to compose optics

let optics: Optics![a.Some.[0]._0] = optics!(a.Some.[0]._0);
// equivalent to optics!(lens_rs::optics::a.lens_rs::optics::Some.[0].lens_rs::optics::_0)
// the default optics path is `lens_rs::optics`.