use std::io::{self, Read}; use std::vec; pub struct Container<'a> { reader: &'a mut dyn Read } impl<'a> Container<'a> { pub fn wrap<'s>(reader: &'s mut dyn io::Read) -> Container<'s> { Container { reader: reader } } pub fn read_to(&mut self, vec: &mut [u8]) { self.reader.read(vec); } } pub fn for_stdin<'a>() -> Container<'a> { let mut r = io::stdin(); Container::wrap(&mut r as &mut dyn io::Read) //~^ ERROR cannot return value referencing local variable } fn main() { let mut c = for_stdin(); let mut v = Vec::new(); c.read_to(v); //~ ERROR E0308 }