Allow inserting a function on any type in a call chain:
any_type
.fun(|o| do_something_with(o))
.other_things();
More detailled example:
```
use {
have::Fun,
itertools::*,
};
fn analyze(loglines: Vec) {
loglines
.iter()
.intogroupmapby(|ll| ll.remoteaddr)
.fun(|g| println!("{} distinct remoteaddresses", g.len()))
.intoiter()
.sortedbykey(|e| Reverse(e.1.len()))
.take(3)
.for_each(|e| println!("{} hits by remote addresse {}", e.1.len(), e.0));
}
```
Usage:
TOML
[dependencies]
have = "0.1"