// Copyright 2026 Jeff Kim <hiking90@gmail.com>
// SPDX-License-Identifier: Apache-2.0
//! What the macros refuse, as the user sees it.
//!
//! The unit tests next to each macro assert the message; these assert that it
//! arrives as a compile error pointing at the offending token, which is the
//! part a user actually experiences.
//!
//! Every case here pins a diagnostic **this crate** authors. A case whose
//! `.stderr` captured rustc's own wording — a trait-bound or borrowck note —
//! would break CI on an unrelated toolchain bump, so those are asserted on the
//! expansion instead (`golden::by_value_argument_is_asserted_copy`).