#![feature(never_type)] fn foo(x: usize, y: !, z: usize) { } fn call_foo_a() { foo(return, 22, 44); //~^ ERROR mismatched types } fn call_foo_b() { // Divergence happens in the argument itself, definitely ok. foo(22, return, 44); } fn call_foo_c() { // This test fails because the divergence happens **after** the // coercion to `!`: foo(22, 44, return); //~ ERROR mismatched types } fn call_foo_d() { // This test passes because `a` has type `!`: let a: ! = return; let b = 22; let c = 44; foo(a, b, c); // ... and hence a reference to `a` is expected to diverge. //~^ ERROR mismatched types } fn call_foo_e() { // This test probably could pass but we don't *know* that `a` // has type `!` so we don't let it work. let a = return; let b = 22; let c = 44; foo(a, b, c); //~ ERROR mismatched types } fn call_foo_f() { // This fn fails because `a` has type `usize`, and hence a // reference to is it **not** considered to diverge. let a: usize = return; let b = 22; let c = 44; foo(a, b, c); //~ ERROR mismatched types } fn array_a() { // Return is coerced to `!` just fine, but `22` cannot be. let x: [!; 2] = [return, 22]; //~ ERROR mismatched types } fn array_b() { // Error: divergence has not yet occurred. let x: [!; 2] = [22, return]; //~ ERROR mismatched types } fn tuple_a() { // No divergence at all. let x: (usize, !, usize) = (22, 44, 66); //~ ERROR mismatched types } fn tuple_b() { // Divergence happens before coercion: OK let x: (usize, !, usize) = (return, 44, 66); //~^ ERROR mismatched types } fn tuple_c() { // Divergence happens before coercion: OK let x: (usize, !, usize) = (22, return, 66); } fn tuple_d() { // Error: divergence happens too late let x: (usize, !, usize) = (22, 44, return); //~ ERROR mismatched types } fn main() { }