For loop vs map in Rust

lib.rs

#![feature(test)]

extern crate test;

use std::net::*;

pub struct Foo {
    a: u8,
    b: u8,
    c: u8,
    d: u8,
}

impl Foo {
    fn addr(self) -> Ipv4Addr {
        Ipv4Addr::new(self.a, self.b, self.c, self.d)
    }
}

pub fn with_for(ip_addresses: Vec<Foo>) -> Vec<IpAddr> {
    let mut result: Vec<IpAddr> = vec![]; // Vec::with_capacity(ip_addresses.len());

    for ip_address in ip_addresses.into_iter() {
        result.push(IpAddr::V4(ip_address.addr()));
    }

    result
}

pub fn with_map(ip_addresses: Vec<Foo>) -> Vec<IpAddr> {
    ip_addresses
        .into_iter()
        .map(|ip_address| IpAddr::V4(ip_address.addr()))
        .collect()
}

#[cfg(test)]
mod tests {
    use super::*;
    use test::Bencher;

    fn prepare() -> Vec<Foo> {
        (1..=255)
            .into_iter()
            .map(|d| Foo {
                a: 127,
                b: 0,
                c: 0,
                d,
            })
            .collect()
    }

    #[bench]
    fn bench_with_for(b: &mut Bencher) {
        b.iter(|| with_for(prepare()));
    }

    #[bench]
    fn bench_with_map(b: &mut Bencher) {
        b.iter(|| with_map(prepare()));
    }
}

ty for sharing