Compilare: warning: unused `std::result::Result` that must be used --> main.rs:106:9 | 106 | write!(self.out, "{}\n", x); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: `#[warn(unused_must_use)]` on by default = note: this `Result` may be an `Err` variant, which should be handled = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info) warning: 1 warning emitted