//! For panicking with formatting in const contexts.
//!
//! This library exists because the panic macro was stabilized for use in const contexts
//! in Rust 1.57.0, without formatting support.
//!
//! All of the types that implement the [`PanicFmt`] trait can be formatted in panics.
//!
//! # Examples
//!
//! - [Basic](#basic)
//! - [Custom Types](#custom-types)
//!
//! ### Basic
//!
//! ```compile_fail
//! use const_panic::concat_panic;
//!
//! const FOO: u32 = 10;
//! const BAR: u32 = 0;
//! const _: () = assert_non_zero(FOO, BAR);
//!
//! #[track_caller]
//! const fn assert_non_zero(foo: u32, bar: u32) {
//!     if foo == 0 || bar == 0 {
//!         concat_panic!("\nneither foo nor bar can be zero!\nfoo: ", foo, "\nbar: ", bar)
//!     }
//! }
//! ```
//! The above code fails to compile with this error:
//! ```text
//! error[E0080]: evaluation of constant value failed
//!  --> src/lib.rs:17:15
//!   |
//! 8 | const _: () = assert_non_zero(FOO, BAR);
//!   |               ^^^^^^^^^^^^^^^^^^^^^^^^^ the evaluated program panicked at '
//! neither foo nor bar can be zero!
//! foo: 10
//! bar: 0', src/lib.rs:8:15
//! ```
//!
//! ### Custom types
//!
//! Panic formatting for custom types can be done in these ways
//! (in increasing order of verbosity):
//! - Using the [`impl_panicfmt`] macro
//! (requires the default-enabled `"non_basic"` feature)
//! - Using the [`flatten_panicvals`] macro
//! (requires the default-enabled `"non_basic"` feature)
//! - Manually implementing the [`PanicFmt`] trait as described in its docs.
//!
//! This example uses the [`impl_panicfmt`] approach.
//!
//! ```compile_fail
//! use const_panic::concat_panic;
//!
//! const LAST: u8 = {
//!     Foo{
//!         x: &[],
//!         y: Bar(false, true),
//!         z: Qux::Left(23),
//!     }.pop().1
//! };
//!
//! impl Foo<'_> {
//!     /// Pops the last element
//!     ///
//!     /// # Panics
//!     ///
//!     /// Panics if `self.x` is empty
//!     #[track_caller]
//!     const fn pop(mut self) -> (Self, u8) {
//!         if let [rem @ .., last] = self.x {
//!             self.x = rem;
//!             (self, *last)
//!         } else {
//!             concat_panic!(
//!                 "\nexpected a non-empty Foo, found: \n",
//!                 // uses alternative Debug formatting for `self`,
//!                 // otherwise this would use regular Debug formatting.
//!                 alt_debug: self
//!             )
//!         }
//!     }
//! }
//!
//! struct Foo<'a> {
//!     x: &'a [u8],
//!     y: Bar,
//!     z: Qux,
//! }
//!
//! // You need to replace non-static lifetimes with `'_` here.
//! const_panic::impl_panicfmt! {
//!     impl Foo<'_>;
//!
//!     struct Foo {
//!         x: &[u8],
//!         y: Bar,
//!         z: Qux,
//!     }
//! }
//!
//! struct Bar(bool, bool);
//!
//! const_panic::impl_panicfmt! {
//!     impl Bar;
//!
//!     struct Bar(bool, bool);
//! }
//!
//! enum Qux {
//!     Up,
//!     Down { x: u32, y: u32 },
//!     Left(u64),
//! }
//!
//! const_panic::impl_panicfmt!{
//!     impl Qux;
//!
//!     enum Qux {
//!         Up,
//!         Down { x: u32, y: u32 },
//!         Left(u64),
//!     }
//! }
//! ```
//! The above code fails to compile with this error:
//! ```text
//! error[E0080]: evaluation of constant value failed
//!   --> src/lib.rs:57:5
//!    |
//! 7  | /     Foo{
//! 8  | |         x: &[],
//! 9  | |         y: Bar(false, true),
//! 10 | |         z: Qux::Left(23),
//! 11 | |     }.pop().1
//!    | |___________^ the evaluated program panicked at '
//! expected a non-empty Foo, found:
//! Foo {
//!     x: [],
//!     y: Bar(
//!         false,
//!         true,
//!     ),
//!     z: Left(
//!         23,
//!     ),
//! }', src/lib.rs:11:7
//!
//!
//! ```
//!
//! # Limitations
#![doc = crate::doc_macros::limitation_docs!()]
//!
//! # Cargo features
//!
//! - `"non_basic"`(enabled by default):
//! Enables support for formatting structs, enums, and arrays.
//! <br>
//! Without this feature, you can effectively only format primitive types
//! (custom types can manually implement formatting with more difficulty).
//!
//! # Plans
//!
//! Adding a derive macro, under an opt-in "derive" feature.
//!
//! # No-std support
//!
//! `const_panic` is `#![no_std]`, it can be used anywhere Rust can be used.
//!
//! # Minimum Supported Rust Version
//!
//! This requires Rust 1.57.0, because it uses the `panic` macro in a const context.
//!
//!
//! [`PanicFmt`]: crate::PanicFmt
//! [`impl_panicfmt`]: crate::impl_panicfmt
//! [`flatten_panicvals`]: crate::flatten_panicvals
#![no_std]
#![cfg_attr(feature = "docsrs", feature(doc_cfg))]
#![warn(missing_docs)]
#![deny(clippy::missing_safety_doc)]
#![deny(clippy::shadow_unrelated)]
#![deny(clippy::wildcard_imports)]

#[macro_use]
mod doc_macros;

#[macro_use]
mod macros;

mod concat_panic_;

mod debug_str_fmt;

pub mod fmt;

mod panic_val;

#[cfg(not(feature = "non_basic"))]
mod utils;

#[cfg(feature = "non_basic")]
#[cfg_attr(feature = "docsrs", doc(cfg(feature = "non_basic")))]
pub mod utils;

#[cfg(all(test, not(feature = "test")))]
compile_error! {r##"please use cargo test --features "test""##}

#[cfg(feature = "non_basic")]
mod slice_stuff;

#[cfg(feature = "non_basic")]
mod array_string;

#[cfg(feature = "non_basic")]
pub use crate::array_string::ArrayString;

mod wrapper;

mod fmt_impls {
    mod basic_fmt_impls;
}

pub use crate::{concat_panic_::concat_panic, panic_val::PanicVal, wrapper::StdWrapper};

#[doc(no_inline)]
pub use crate::fmt::{FmtArg, IsCustomType, PanicFmt};

#[cfg(feature = "non_basic")]
#[doc(no_inline)]
pub use crate::fmt::{ComputePvCount, TypeDelim};

#[doc(hidden)]
pub mod __ {
    pub use core::{compile_error, concat, primitive::usize, stringify};

    pub use crate::fmt::{FmtArg, PanicFmt};

    #[cfg(feature = "non_basic")]
    pub use crate::utils::{assert_flatten_panicvals_length, flatten_panicvals, panicvals_id};
}

#[doc(hidden)]
#[cfg(feature = "test")]
pub mod test_utils;

#[doc(hidden)]
#[cfg(feature = "test")]
pub mod for_tests {
    pub use crate::concat_panic_::{format_panic_message, NotEnoughSpace};
}