Add File::open_with() function to open files with options (e.g. read/write)

[Timmmm]

The current way to open a file is this:

File::open("foo.txt")

But if you want to open a file in with any options you do this:

use std::fs::OpenOptions;

let mut file = OpenOptions::new()
    .read(true)
    .write(true)
    .open("foo.txt");

It's weird that the options object does the actual opening. I propose that we deprecate OpenOptions::open() and add File::open_with(path: &str, options: &OpenOptions).

let mut file = File::open_with("foo.txt", OpenOptions::new().read().write());

[steveklabnik]

I'm not on the libs team, but this feels RFC-worthy to me.

[Mark-Simulacrum]

Closing in favor of #65439.