library/std/src/sys/env/unsupported.rs

use crate::ffi::{OsStr, OsString};
use crate::{fmt, io};

pub struct Env(!);

impl fmt::Debug for Env {
    fn fmt(&self, _: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.0
    }
}

impl Iterator for Env {
    type Item = (OsString, OsString);
    fn next(&mut self) -> Option<(OsString, OsString)> {
        self.0
    }
}

pub fn env() -> Env {
    panic!("not supported on this platform")
}

pub fn getenv(_: &OsStr) -> Option<OsString> {
    None
}

pub unsafe fn setenv(_: &OsStr, _: &OsStr) -> io::Result<()> {
    Err(io::const_error!(io::ErrorKind::Unsupported, "cannot set env vars on this platform"))
}

pub unsafe fn unsetenv(_: &OsStr) -> io::Result<()> {
    Err(io::const_error!(io::ErrorKind::Unsupported, "cannot unset env vars on this platform"))
}