#![feature(cfg_select)] #![crate_type = "lib"] fn print() { println!(cfg_select! { unix => { "unix" } _ => { "not unix" } }); } fn arm_rhs_must_be_in_braces() -> i32 { cfg_select! { true => 1 //~^ ERROR: expected `{`, found `1` } } cfg_select! { _ => {} true => {} //~^ WARN unreachable predicate } cfg_select! { //~^ ERROR none of the predicates in this `cfg_select` evaluated to true false => {} } cfg_select! {} //~^ ERROR none of the predicates in this `cfg_select` evaluated to true