// This test is a regression test for a bug where we only checked function calls in no-const // functions for `rustc_args_required_const` arguments. This meant that even though `bar` needs its // argument to be const, inside a const fn (callable at runtime), the value for it may come from a // non-constant (namely an argument to the const fn). #![feature(rustc_attrs)] const fn foo(a: i32) { bar(a); //~ ERROR argument 1 is required to be a constant } #[rustc_args_required_const(0)] const fn bar(_: i32) {} fn main() { // this function call will pass a runtime-value (number of program arguments) to `foo`, which // will in turn forward it to `bar`, which expects a compile-time argument foo(std::env::args().count() as i32); }