<commit_before>#[doc = include_str!("panic.md")]
#[macro_export]
#[rustc_builtin_macro = "core_panic"]
#[allow_internal_unstable(edition_panic)]
#[stable(feature = "core", since = "1.6.0")]
#[rustc_diagnostic_item = "core_panic_macro"]
macro_rules! panic {
    // Expands to either `$crate::panic::panic_2015` or `$crate::panic::panic_2021`
    // depending on the edition of the caller.
    ($($arg:tt)*) => {
        /* compiler built-in */
    };
}

/// Asserts that two expressions are equal to each other (using [`PartialEq`]).
///
/// On panic, this macro will print the values of the expressions with their
/// debug representations.
///
/// Like [`assert!`], this macro has a second form, where a custom
/// panic message can be provided.
///
/// # Examples
///
/// ```
/// let a = 3;
/// let b = 1 + 2;
/// assert_eq!(a, b);
///
/// assert_eq!(a, b, "we are testing addition with {} and {}", a, b);
/// ```
#[macro_export]
#[stable(feature = "rust1", since = "1.0.0")]
#[allow_internal_unstable(core_panic)]
macro_rules! assert_eq {
    ($left:expr, $right:expr $(,)?) => ({
        match (&$left, &$right) {
            (left_val, right_val) => {
                if !(*left_val == *right_val) {
                    let kind = $crate::panicking::AssertKind::Eq;
                    // The reborrows below are intentional. Without them, the stack slot for the
                    // borrow is initialized even before the values are compared, leading to a
                    // noticeable slow down.
                    $crate::panicking::assert_failed(kind, &*left_val, &*right_val, $crate::option::Option::None);
                }
            }
        }
    });
    ($left:expr, $right:expr, $($arg:tt)+) => ({
        match (&$left, &$right) {
            (left_val, right_val) => {
                if !(*left_val == *right_val) {
                    let kind = $crate::panicking::AssertKind::Eq;
                    // The reborrows below are intentional. Without them, the stack slot for the
                    // borrow is initialized even before the values are compared, leading to a
                    // noticeable slow down.
                    $crate::panicking::assert_failed(kind, &*left_val, &*right_val, $crate::option::Option::Some($crate::format_args!($($arg)+)));
                }
            }
        }
    });
}

/// Asserts that two expressions are not equal to each other (using [`PartialEq`]).
///
/// On panic, this macro will print the values of the expressions with their
/// debug representations.
///
/// Like [`assert!`], this macro has a second form, where a custom
/// panic message can be provided.
///
/// # Examples
///
/// ```
/// let a = 3;
/// let b = 2;
/// assert_ne!(a, b);
///
/// assert_ne!(a, b, "we are testing that the values are not equal");
/// ```
#[macro_export]
#[stable(feature = "assert_ne", since = "1.13.0")]
#[allow_internal_unstable(core_panic)]
macro_rules! assert_ne {
    ($left:expr, $right:expr $(,)?) => ({
        match (&$left, &$right) {
            (left_val, right_val) => {
                if *left_val == *right_val {
                    let kind = $crate::panicking::AssertKind::Ne;
                    // The reborrows below are intentional. Without them, the stack slot for the
                    // borrow is initialized even before the values are compared, leading to a
                    // noticeable slow down.
                    $crate::panicking::assert_failed(kind, &*left_val, &*right_val, $crate::option::Option::None);
                }
            }
        }
    });
    ($left:expr, $right:expr, $($arg:tt)+) => ({
        match (&($left), &($right)) {
            (left_val, right_val) => {
                if *left_val == *right_val {
                    let kind = $crate::panicking::AssertKind::Ne;
                    // The reborrows below are intentional. Without them, the stack slot for the
                    // borrow is initialized even before the values are compared, leading to a
                    // noticeable slow down.
                    $crate::panicking::assert_failed(kind, &*left_val, &*right_val, $crate::option::Option::Some($crate::format_args!($($arg)+)));
                }
            }
        }
    });
}

/// Asserts that an expression matches any of the given patterns.
///
/// Like in a `match` expression, the pattern can be optionally followed by `if`
/// and a guard expression that has access to names bound by the pattern.
///
/// On panic, this macro will print the value of the expression with its
/// debug representation.
///
/// Like [`assert!`], this macro has a second form, where a custom
/// panic message can be provided.
///
/// # Examples
///
/// ```
/// #![feature(assert_matches)]
///
/// let a = 1u32.checked_add(2);
/// let b = 1u32.checked_sub(2);
/// assert_matches!(a, Some(_));
/// assert_matches!(b, None);
///
/// let c = Ok("abc".to_string());
/// assert_matches!(c, Ok(x) | Err(x) if x.len() < 100);
/// ```
#[macro_export]
#[unstable(feature = "assert_matches", issue = "82775")]
#[allow_internal_unstable(core_panic)]
macro_rules! assert_matches {
    ($left:expr, $( $pattern:pat )|+ $( if $guard: expr )? $(,)?) => ({
        match $left {
            $( $pattern )|+ $( if $guard )? => {}
            ref left_val => {
                $crate::panicking::assert_matches_failed(
                    left_val,
                    $crate::stringify!($($pattern)|+ $(if $guard)?),
                    $crate::option::Option::None
                );
            }
        }
    });
    ($left:expr, $( $pattern:pat )|+ $( if $guard: expr )?, $($arg:tt)+) => ({
        match $left {
            $( $pattern )|+ $( if $guard )? => {}
            ref left_val => {
                $crate::panicking::assert_matches_failed(
                    left_val,
                    $crate::stringify!($($pattern)|+ $(if $guard)?),
                    $crate::option::Option::Some($crate::format_args!($($arg)+))
                );
            }
        }
    });
}

/// Asserts that a boolean expression is `true` at runtime.
///
/// This will invoke the [`panic!`] macro if the provided expression cannot be
/// evaluated to `true` at runtime.
///
/// Like [`assert!`], this macro also has a second version, where a custom panic
/// message can be provided.
///
/// # Uses
///
/// Unlike [`assert!`], `debug_assert!` statements are only enabled in non
/// optimized builds by default. An optimized build will not execute
/// `debug_assert!` statements unless `-C debug-assertions` is passed to the
/// compiler. This makes `debug_assert!` useful for checks that are too
/// expensive to be present in a release build but may be helpful during
/// development. The result of expanding `debug_assert!` is always type checked.
///
/// An unchecked assertion allows a program in an inconsistent state to keep
/// running, which might have unexpected consequences but does not introduce
/// unsafety as long as this only happens in safe code. The performance cost
/// of assertions, however, is not measurable in general. Replacing [`assert!`]
/// with `debug_assert!` is thus only encouraged after thorough profiling, and
/// more importantly, only in safe code!
///
/// # Examples
///
/// ```
/// // the panic message for these assertions is the stringified value of the
/// // expression given.
/// debug_assert!(true);
///
/// fn some_expensive_computation() -> bool { true } // a very simple function
/// debug_assert!(some_expensive_computation());
///
/// // assert with a custom message
/// let x = true;
/// debug_assert!(x, "x wasn't true!");
///
/// let a = 3; let b = 27;
/// debug_assert!(a + b == 30, "a = {}, b = {}", a, b);
/// ```
#[macro_export]
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_diagnostic_item = "debug_assert_macro"]
macro_rules! debug_assert {
    ($($arg:tt)*) => (if $crate::cfg!(debug_assertions) { $crate::assert!($($arg)*); })
}

/// Asserts that two expressions are equal to each other.
///
/// On panic, this macro will print the values of the expressions with their
/// debug representations.
///
/// Unlike [`assert_eq!`], `debug_assert_eq!` statements are only enabled in non
/// optimized builds by default. An optimized build will not execute
/// `debug_assert_eq!` statements unless `-C debug-assertions` is passed to the
/// compiler. This makes `debug_assert_eq!` useful for checks that are too
/// expensive to be present in a release build but may be helpful during
/// development. The result of expanding `debug_assert_eq!` is always type checked.
///
/// # Examples
///
/// ```
/// let a = 3;
/// let b = 1 + 2;
/// debug_assert_eq!(a, b);
/// ```
#[macro_export]
#[stable(feature = "rust1", since = "1.0.0")]
macro_rules! debug_assert_eq {
    ($($arg:tt)*) => (if $crate::cfg!(debug_assertions) { $crate::assert_eq!($($arg)*); })
}

/// Asserts that two expressions are not equal to each other.
///
/// On panic, this macro will print the values of the expressions with their
/// debug representations.
///
/// Unlike [`assert_ne!`], `debug_assert_ne!` statements are only enabled in non
/// optimized builds by default. An optimized build will not execute
/// `debug_assert_ne!` statements unless `-C debug-assertions` is passed to the
/// compiler. This makes `debug_assert_ne!` useful for checks that are too
/// expensive to be present in a release build but may be helpful during
/// development. The result of expanding `debug_assert_ne!` is always type checked.
///
/// # Examples
///
/// ```
/// let a = 3;
/// let b = 2;
/// debug_assert_ne!(a, b);
/// ```
#[macro_export]
#[stable(feature = "assert_ne", since = "1.13.0")]
macro_rules! debug_assert_ne {
    ($($arg:tt)*) => (if $crate::cfg!(debug_assertions) { $crate::assert_ne!($($arg)*); })
}

/// Asserts that an expression matches any of the given patterns.
///
/// Like in a `match` expression, the pattern can be optionally followed by `if`
/// and a guard expression that has access to names bound by the pattern.
///
/// On panic, this macro will print the value of the expression with its
/// debug representation.
///
/// Unlike [`assert_matches!`], `debug_assert_matches!` statements are only
/// enabled in non optimized builds by default. An optimized build will not
/// execute `debug_assert_matches!` statements unless `-C debug-assertions` is
/// passed to the compiler. This makes `debug_assert_matches!` useful for
/// checks that are too expensive to be present in a release build but may be
/// helpful during development. The result of expanding `debug_assert_matches!`
/// is always type checked.
///
/// # Examples
///
/// ```
/// #![feature(assert_matches)]
///
/// let a = 1u32.checked_add(2);
/// let b = 1u32.checked_sub(2);
/// debug_assert_matches!(a, Some(_));
/// debug_assert_matches!(b, None);
///
/// let c = Ok("abc".to_string());
/// debug_assert_matches!(c, Ok(x) | Err(x) if x.len() < 100);
/// ```
#[macro_export]
#[unstable(feature = "assert_matches", issue = "82775")]
#[allow_internal_unstable(assert_matches)]
macro_rules! debug_assert_matches {
    ($($arg:tt)*) => (if $crate::cfg!(debug_assertions) { $crate::assert_matches!($($arg)*); })
}

/// Returns whether the given expression matches any of the given patterns.
///
/// Like in a `match` expression, the pattern can be optionally followed by `if`
/// and a guard expression that has access to names bound by the pattern.
///
/// # Examples
///
/// ```
/// let foo = 'f';
/// assert!(matches!(foo, 'A'..='Z' | 'a'..='z'));
///
/// let bar = Some(4);
/// assert!(matches!(bar, Some(x) if x > 2));
/// ```
#[macro_export]
#[stable(feature = "matches_macro", since = "1.42.0")]
macro_rules! matches {
    ($expression:expr, $( $pattern:pat )|+ $( if $guard: expr )? $(,)?) => {
        match $expression {
            $( $pattern )|+ $( if $guard )? => true,
            _ => false
        }
    }
}

/// Unwraps a result or propagates its error.
///
/// The `?` operator was added to replace `try!` and should be used instead.
/// Furthermore, `try` is a reserved word in Rust 2018, so if you must use
/// it, you will need to use the [raw-identifier syntax][ris]: `r#try`.
///
/// [ris]: https://doc.rust-lang.org/nightly/rust-by-example/compatibility/raw_identifiers.html
///
/// `try!` matches the given [`Result`]. In case of the `Ok` variant, the
/// expression has the value of the wrapped value.
///
/// In case of the `Err` variant, it retrieves the inner error. `try!` then
/// performs conversion using `From`. This provides automatic conversion
/// between specialized errors and more general ones. The resulting
/// error is then immediately returned.
///
/// Because of the early return, `try!` can only be used in functions that
/// return [`Result`].
///
/// # Examples
///
/// ```
/// use std::io;
/// use std::fs::File;
/// use std::io::prelude::*;
///
/// enum MyError {
///     FileWriteError
/// }
///
/// impl From<io::Error> for MyError {
///     fn from(e: io::Error) -> MyError {
///         MyError::FileWriteError
///     }
/// }
///
/// // The preferred method of quick returning Errors
/// fn write_to_file_question() -> Result<(), MyError> {
///     let mut file = File::create("my_best_friends.txt")?;
///     file.write_all(b"This is a list of my best friends.")?;
///     Ok(())
/// }
///
/// // The previous method of quick returning Errors
/// fn write_to_file_using_try() -> Result<(), MyError> {
///     let mut file = r#try!(File::create("my_best_friends.txt"));
///     r#try!(file.write_all(b"This is a list of my best friends."));
///     Ok(())
/// }
///
/// // This is equivalent to:
/// fn write_to_file_using_match() -> Result<(), MyError> {
///     let mut file = r#try!(File::create("my_best_friends.txt"));
///     match file.write_all(b"This is a list of my best friends.") {
///         Ok(v) => v,
///         Err(e) => return Err(From::from(e)),
///     }
///     Ok(())
/// }
/// ```
#[macro_export]
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_deprecated(since = "1.39.0", reason = "use the `?` operator instead")]
#[doc(alias = "?")]
macro_rules! r#try {
    ($expr:expr $(,)?) => {
        match $expr {
            $crate::result::Result::Ok(val) => val,
            $crate::result::Result::Err(err) => {
                return $crate::result::Result::Err($crate::convert::From::from(err));
            }
        }
    };
}

/// Writes formatted data into a buffer.
///
/// This macro accepts a 'writer', a format string, and a list of arguments. Arguments will be
/// formatted according to the specified format string and the result will be passed to the writer.
/// The writer may be any value with a `write_fmt` method; generally this comes from an
/// implementation of either the [`fmt::Write`] or the [`io::Write`] trait. The macro
/// returns whatever the `write_fmt` method returns; commonly a [`fmt::Result`], or an
/// [`io::Result`].
///
/// See [`std::fmt`] for more information on the format string syntax.
///
/// [`std::fmt`]: ../std/fmt/index.html
/// [`fmt::Write`]: crate::fmt::Write
/// [`io::Write`]: ../std/io/trait.Write.html
/// [`fmt::Result`]: crate::fmt::Result
/// [`io::Result`]: ../std/io/type.Result.html
///
/// # Examples
///
/// ```
/// use std::io::Write;
///
/// fn main() -> std::io::Result<()> {
///     let mut w = Vec::new();
///     write!(&mut w, "test")?;
///     write!(&mut w, "formatted {}", "arguments")?;
///
///     assert_eq!(w, b"testformatted arguments");
///     Ok(())
/// }
/// ```
///
/// A module can import both `std::fmt::Write` and `std::io::Write` and call `write!` on objects
/// implementing either, as objects do not typically implement both. However, the module must
/// import the traits qualified so their names do not conflict:
///
/// ```
/// use std::fmt::Write as FmtWrite;
/// use std::io::Write as IoWrite;
///
/// fn main() -> Result<(), Box<dyn std::error::Error>> {
///     let mut s = String::new();
///     let mut v = Vec::new();
///
///     write!(&mut s, "{} {}", "abc", 123)?; // uses fmt::Write::write_fmt
///     write!(&mut v, "s = {:?}", s)?; // uses io::Write::write_fmt
///     assert_eq!(v, b"s = \"abc 123\"");
///     Ok(())
/// }
/// ```
///
/// Note: This macro can be used in `no_std` setups as well.
/// In a `no_std` setup you are responsible for the implementation details of the components.
///
/// ```no_run
/// # extern crate core;
/// use core::fmt::Write;
///
/// struct Example;
///
/// impl Write for Example {
///     fn write_str(&mut self, _s: &str) -> core::fmt::Result {
///          unimplemented!();
///     }
/// }
///
/// let mut m = Example{};
/// write!(&mut m, "Hello World").expect("Not written");
/// ```
#[macro_export]
#[stable(feature = "rust1", since = "1.0.0")]
macro_rules! write {
    ($dst:expr, $($arg:tt)*) => ($dst.write_fmt($crate::format_args!($($arg)*)))
}

/// Write formatted data into a buffer, with a newline appended.
///
/// On all platforms, the newline is the LINE FEED character (`\n`/`U+000A`) alone
/// (no additional CARRIAGE RETURN (`\r`/`U+000D`).
///
/// For more information, see [`write!`]. For information on the format string syntax, see
/// [`std::fmt`].
///
/// [`std::fmt`]: ../std/fmt/index.html
///
/// # Examples
///
/// ```
/// use std::io::{Write, Result};
///
/// fn main() -> Result<()> {
///     let mut w = Vec::new();
///     writeln!(&mut w)?;
///     writeln!(&mut w, "test")?;
///     writeln!(&mut w, "formatted {}", "arguments")?;
///
///     assert_eq!(&w[..], "\ntest\nformatted arguments\n".as_bytes());
///     Ok(())
/// }
/// ```
///
/// A module can import both `std::fmt::Write` and `std::io::Write` and call `write!` on objects
/// implementing either, as objects do not typically implement both. However, the module must
/// import the traits qualified so their names do not conflict:
///
/// ```
/// use std::fmt::Write as FmtWrite;
/// use std::io::Write as IoWrite;
///
/// fn main() -> Result<(), Box<dyn std::error::Error>> {
///     let mut s = String::new();
///     let mut v = Vec::new();
///
///     writeln!(&mut s, "{} {}", "abc", 123)?; // uses fmt::Write::write_fmt
///     writeln!(&mut v, "s = {:?}", s)?; // uses io::Write::write_fmt
///     assert_eq!(v, b"s = \"abc 123\\n\"\n");
///     Ok(())
/// }
/// ```
#[macro_export]
#[stable(feature = "rust1", since = "1.0.0")]
#[allow_internal_unstable(format_args_nl)]
macro_rules! writeln {
    ($dst:expr $(,)?) => (
        $crate::write!($dst, "\n")
    );
    ($dst:expr, $($arg:tt)*) => (
        $dst.write_fmt($crate::format_args_nl!($($arg)*))
    );
}

/// Indicates unreachable code.
///
/// This is useful any time that the compiler can't determine that some code is unreachable. For
/// example:
///
/// * Match arms with guard conditions.
/// * Loops that dynamically terminate.
/// * Iterators that dynamically terminate.
///
/// If the determination that the code is unreachable proves incorrect, the
/// program immediately terminates with a [`panic!`].
///
/// The unsafe counterpart of this macro is the [`unreachable_unchecked`] function, which
/// will cause undefined behavior if the code is reached.
///
/// [`unreachable_unchecked`]: crate::hint::unreachable_unchecked
///
/// # Panics
///
/// This will always [`panic!`].
///
/// # Examples
///
/// Match arms:
///
/// ```
/// # #[allow(dead_code)]
/// fn foo(x: Option<i32>) {
///     match x {
///         Some(n) if n >= 0 => println!("Some(Non-negative)"),
///         Some(n) if n <  0 => println!("Some(Negative)"),
///         Some(_)           => unreachable!(), // compile error if commented out
///         None              => println!("None")
///     }
/// }
/// ```
///
/// Iterators:
///
/// ```
/// # #[allow(dead_code)]
/// fn divide_by_three(x: u32) -> u32 { // one of the poorest implementations of x/3
///     for i in 0.. {
///         if 3*i < i { panic!("u32 overflow"); }
///         if x < 3*i { return i-1; }
///     }
///     unreachable!();
/// }
/// ```
#[macro_export]
#[stable(feature = "rust1", since = "1.0.0")]
macro_rules! unreachable {
    () => ({
        $crate::panic!("internal error: entered unreachable code")
    });
    ($msg:expr $(,)?) => ({
        $crate::unreachable!("{}", $msg)
    });
    ($fmt:expr, $($arg:tt)*) => ({
        $crate::panic!($crate::concat!("internal error: entered unreachable code: ", $fmt), $($arg)*)
    });
}

/// Indicates unimplemented code by panicking with a message of "not implemented".
///
/// This allows your code to type-check, which is useful if you are prototyping or
/// implementing a trait that requires multiple methods which you don't plan of using all of.
///
/// The difference between `unimplemented!` and [`todo!`] is that while `todo!`
/// conveys an intent of implementing the functionality later and the message is "not yet
/// implemented", `unimplemented!` makes no such claims. Its message is "not implemented".
/// Also some IDEs will mark `todo!`s.
///
/// # Panics
///
/// This will always [`panic!`] because `unimplemented!` is just a shorthand for `panic!` with a
/// fixed, specific message.
///
/// Like `panic!`, this macro has a second form for displaying custom values.
///
/// # Examples
///
/// Say we have a trait `Foo`:<commit_msg>Rollup merge of #85644 - tialaramex:master, r=dtolnay<commit_after>#[doc = include_str!("panic.md")]
#[macro_export]
#[rustc_builtin_macro = "core_panic"]
#[allow_internal_unstable(edition_panic)]
#[stable(feature = "core", since = "1.6.0")]
#[rustc_diagnostic_item = "core_panic_macro"]
macro_rules! panic {
    // Expands to either `$crate::panic::panic_2015` or `$crate::panic::panic_2021`
    // depending on the edition of the caller.
    ($($arg:tt)*) => {
        /* compiler built-in */
    };
}

/// Asserts that two expressions are equal to each other (using [`PartialEq`]).
///
/// On panic, this macro will print the values of the expressions with their
/// debug representations.
///
/// Like [`assert!`], this macro has a second form, where a custom
/// panic message can be provided.
///
/// # Examples
///
/// ```
/// let a = 3;
/// let b = 1 + 2;
/// assert_eq!(a, b);
///
/// assert_eq!(a, b, "we are testing addition with {} and {}", a, b);
/// ```
#[macro_export]
#[stable(feature = "rust1", since = "1.0.0")]
#[allow_internal_unstable(core_panic)]
macro_rules! assert_eq {
    ($left:expr, $right:expr $(,)?) => ({
        match (&$left, &$right) {
            (left_val, right_val) => {
                if !(*left_val == *right_val) {
                    let kind = $crate::panicking::AssertKind::Eq;
                    // The reborrows below are intentional. Without them, the stack slot for the
                    // borrow is initialized even before the values are compared, leading to a
                    // noticeable slow down.
                    $crate::panicking::assert_failed(kind, &*left_val, &*right_val, $crate::option::Option::None);
                }
            }
        }
    });
    ($left:expr, $right:expr, $($arg:tt)+) => ({
        match (&$left, &$right) {
            (left_val, right_val) => {
                if !(*left_val == *right_val) {
                    let kind = $crate::panicking::AssertKind::Eq;
                    // The reborrows below are intentional. Without them, the stack slot for the
                    // borrow is initialized even before the values are compared, leading to a
                    // noticeable slow down.
                    $crate::panicking::assert_failed(kind, &*left_val, &*right_val, $crate::option::Option::Some($crate::format_args!($($arg)+)));
                }
            }
        }
    });
}

/// Asserts that two expressions are not equal to each other (using [`PartialEq`]).
///
/// On panic, this macro will print the values of the expressions with their
/// debug representations.
///
/// Like [`assert!`], this macro has a second form, where a custom
/// panic message can be provided.
///
/// # Examples
///
/// ```
/// let a = 3;
/// let b = 2;
/// assert_ne!(a, b);
///
/// assert_ne!(a, b, "we are testing that the values are not equal");
/// ```
#[macro_export]
#[stable(feature = "assert_ne", since = "1.13.0")]
#[allow_internal_unstable(core_panic)]
macro_rules! assert_ne {
    ($left:expr, $right:expr $(,)?) => ({
        match (&$left, &$right) {
            (left_val, right_val) => {
                if *left_val == *right_val {
                    let kind = $crate::panicking::AssertKind::Ne;
                    // The reborrows below are intentional. Without them, the stack slot for the
                    // borrow is initialized even before the values are compared, leading to a
                    // noticeable slow down.
                    $crate::panicking::assert_failed(kind, &*left_val, &*right_val, $crate::option::Option::None);
                }
            }
        }
    });
    ($left:expr, $right:expr, $($arg:tt)+) => ({
        match (&($left), &($right)) {
            (left_val, right_val) => {
                if *left_val == *right_val {
                    let kind = $crate::panicking::AssertKind::Ne;
                    // The reborrows below are intentional. Without them, the stack slot for the
                    // borrow is initialized even before the values are compared, leading to a
                    // noticeable slow down.
                    $crate::panicking::assert_failed(kind, &*left_val, &*right_val, $crate::option::Option::Some($crate::format_args!($($arg)+)));
                }
            }
        }
    });
}

/// Asserts that an expression matches any of the given patterns.
///
/// Like in a `match` expression, the pattern can be optionally followed by `if`
/// and a guard expression that has access to names bound by the pattern.
///
/// On panic, this macro will print the value of the expression with its
/// debug representation.
///
/// Like [`assert!`], this macro has a second form, where a custom
/// panic message can be provided.
///
/// # Examples
///
/// ```
/// #![feature(assert_matches)]
///
/// let a = 1u32.checked_add(2);
/// let b = 1u32.checked_sub(2);
/// assert_matches!(a, Some(_));
/// assert_matches!(b, None);
///
/// let c = Ok("abc".to_string());
/// assert_matches!(c, Ok(x) | Err(x) if x.len() < 100);
/// ```
#[macro_export]
#[unstable(feature = "assert_matches", issue = "82775")]
#[allow_internal_unstable(core_panic)]
macro_rules! assert_matches {
    ($left:expr, $( $pattern:pat )|+ $( if $guard: expr )? $(,)?) => ({
        match $left {
            $( $pattern )|+ $( if $guard )? => {}
            ref left_val => {
                $crate::panicking::assert_matches_failed(
                    left_val,
                    $crate::stringify!($($pattern)|+ $(if $guard)?),
                    $crate::option::Option::None
                );
            }
        }
    });
    ($left:expr, $( $pattern:pat )|+ $( if $guard: expr )?, $($arg:tt)+) => ({
        match $left {
            $( $pattern )|+ $( if $guard )? => {}
            ref left_val => {
                $crate::panicking::assert_matches_failed(
                    left_val,
                    $crate::stringify!($($pattern)|+ $(if $guard)?),
                    $crate::option::Option::Some($crate::format_args!($($arg)+))
                );
            }
        }
    });
}

/// Asserts that a boolean expression is `true` at runtime.
///
/// This will invoke the [`panic!`] macro if the provided expression cannot be
/// evaluated to `true` at runtime.
///
/// Like [`assert!`], this macro also has a second version, where a custom panic
/// message can be provided.
///
/// # Uses
///
/// Unlike [`assert!`], `debug_assert!` statements are only enabled in non
/// optimized builds by default. An optimized build will not execute
/// `debug_assert!` statements unless `-C debug-assertions` is passed to the
/// compiler. This makes `debug_assert!` useful for checks that are too
/// expensive to be present in a release build but may be helpful during
/// development. The result of expanding `debug_assert!` is always type checked.
///
/// An unchecked assertion allows a program in an inconsistent state to keep
/// running, which might have unexpected consequences but does not introduce
/// unsafety as long as this only happens in safe code. The performance cost
/// of assertions, however, is not measurable in general. Replacing [`assert!`]
/// with `debug_assert!` is thus only encouraged after thorough profiling, and
/// more importantly, only in safe code!
///
/// # Examples
///
/// ```
/// // the panic message for these assertions is the stringified value of the
/// // expression given.
/// debug_assert!(true);
///
/// fn some_expensive_computation() -> bool { true } // a very simple function
/// debug_assert!(some_expensive_computation());
///
/// // assert with a custom message
/// let x = true;
/// debug_assert!(x, "x wasn't true!");
///
/// let a = 3; let b = 27;
/// debug_assert!(a + b == 30, "a = {}, b = {}", a, b);
/// ```
#[macro_export]
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_diagnostic_item = "debug_assert_macro"]
macro_rules! debug_assert {
    ($($arg:tt)*) => (if $crate::cfg!(debug_assertions) { $crate::assert!($($arg)*); })
}

/// Asserts that two expressions are equal to each other.
///
/// On panic, this macro will print the values of the expressions with their
/// debug representations.
///
/// Unlike [`assert_eq!`], `debug_assert_eq!` statements are only enabled in non
/// optimized builds by default. An optimized build will not execute
/// `debug_assert_eq!` statements unless `-C debug-assertions` is passed to the
/// compiler. This makes `debug_assert_eq!` useful for checks that are too
/// expensive to be present in a release build but may be helpful during
/// development. The result of expanding `debug_assert_eq!` is always type checked.
///
/// # Examples
///
/// ```
/// let a = 3;
/// let b = 1 + 2;
/// debug_assert_eq!(a, b);
/// ```
#[macro_export]
#[stable(feature = "rust1", since = "1.0.0")]
macro_rules! debug_assert_eq {
    ($($arg:tt)*) => (if $crate::cfg!(debug_assertions) { $crate::assert_eq!($($arg)*); })
}

/// Asserts that two expressions are not equal to each other.
///
/// On panic, this macro will print the values of the expressions with their
/// debug representations.
///
/// Unlike [`assert_ne!`], `debug_assert_ne!` statements are only enabled in non
/// optimized builds by default. An optimized build will not execute
/// `debug_assert_ne!` statements unless `-C debug-assertions` is passed to the
/// compiler. This makes `debug_assert_ne!` useful for checks that are too
/// expensive to be present in a release build but may be helpful during
/// development. The result of expanding `debug_assert_ne!` is always type checked.
///
/// # Examples
///
/// ```
/// let a = 3;
/// let b = 2;
/// debug_assert_ne!(a, b);
/// ```
#[macro_export]
#[stable(feature = "assert_ne", since = "1.13.0")]
macro_rules! debug_assert_ne {
    ($($arg:tt)*) => (if $crate::cfg!(debug_assertions) { $crate::assert_ne!($($arg)*); })
}

/// Asserts that an expression matches any of the given patterns.
///
/// Like in a `match` expression, the pattern can be optionally followed by `if`
/// and a guard expression that has access to names bound by the pattern.
///
/// On panic, this macro will print the value of the expression with its
/// debug representation.
///
/// Unlike [`assert_matches!`], `debug_assert_matches!` statements are only
/// enabled in non optimized builds by default. An optimized build will not
/// execute `debug_assert_matches!` statements unless `-C debug-assertions` is
/// passed to the compiler. This makes `debug_assert_matches!` useful for
/// checks that are too expensive to be present in a release build but may be
/// helpful during development. The result of expanding `debug_assert_matches!`
/// is always type checked.
///
/// # Examples
///
/// ```
/// #![feature(assert_matches)]
///
/// let a = 1u32.checked_add(2);
/// let b = 1u32.checked_sub(2);
/// debug_assert_matches!(a, Some(_));
/// debug_assert_matches!(b, None);
///
/// let c = Ok("abc".to_string());
/// debug_assert_matches!(c, Ok(x) | Err(x) if x.len() < 100);
/// ```
#[macro_export]
#[unstable(feature = "assert_matches", issue = "82775")]
#[allow_internal_unstable(assert_matches)]
macro_rules! debug_assert_matches {
    ($($arg:tt)*) => (if $crate::cfg!(debug_assertions) { $crate::assert_matches!($($arg)*); })
}

/// Returns whether the given expression matches any of the given patterns.
///
/// Like in a `match` expression, the pattern can be optionally followed by `if`
/// and a guard expression that has access to names bound by the pattern.
///
/// # Examples
///
/// ```
/// let foo = 'f';
/// assert!(matches!(foo, 'A'..='Z' | 'a'..='z'));
///
/// let bar = Some(4);
/// assert!(matches!(bar, Some(x) if x > 2));
/// ```
#[macro_export]
#[stable(feature = "matches_macro", since = "1.42.0")]
macro_rules! matches {
    ($expression:expr, $( $pattern:pat )|+ $( if $guard: expr )? $(,)?) => {
        match $expression {
            $( $pattern )|+ $( if $guard )? => true,
            _ => false
        }
    }
}

/// Unwraps a result or propagates its error.
///
/// The `?` operator was added to replace `try!` and should be used instead.
/// Furthermore, `try` is a reserved word in Rust 2018, so if you must use
/// it, you will need to use the [raw-identifier syntax][ris]: `r#try`.
///
/// [ris]: https://doc.rust-lang.org/nightly/rust-by-example/compatibility/raw_identifiers.html
///
/// `try!` matches the given [`Result`]. In case of the `Ok` variant, the
/// expression has the value of the wrapped value.
///
/// In case of the `Err` variant, it retrieves the inner error. `try!` then
/// performs conversion using `From`. This provides automatic conversion
/// between specialized errors and more general ones. The resulting
/// error is then immediately returned.
///
/// Because of the early return, `try!` can only be used in functions that
/// return [`Result`].
///
/// # Examples
///
/// ```
/// use std::io;
/// use std::fs::File;
/// use std::io::prelude::*;
///
/// enum MyError {
///     FileWriteError
/// }
///
/// impl From<io::Error> for MyError {
///     fn from(e: io::Error) -> MyError {
///         MyError::FileWriteError
///     }
/// }
///
/// // The preferred method of quick returning Errors
/// fn write_to_file_question() -> Result<(), MyError> {
///     let mut file = File::create("my_best_friends.txt")?;
///     file.write_all(b"This is a list of my best friends.")?;
///     Ok(())
/// }
///
/// // The previous method of quick returning Errors
/// fn write_to_file_using_try() -> Result<(), MyError> {
///     let mut file = r#try!(File::create("my_best_friends.txt"));
///     r#try!(file.write_all(b"This is a list of my best friends."));
///     Ok(())
/// }
///
/// // This is equivalent to:
/// fn write_to_file_using_match() -> Result<(), MyError> {
///     let mut file = r#try!(File::create("my_best_friends.txt"));
///     match file.write_all(b"This is a list of my best friends.") {
///         Ok(v) => v,
///         Err(e) => return Err(From::from(e)),
///     }
///     Ok(())
/// }
/// ```
#[macro_export]
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_deprecated(since = "1.39.0", reason = "use the `?` operator instead")]
#[doc(alias = "?")]
macro_rules! r#try {
    ($expr:expr $(,)?) => {
        match $expr {
            $crate::result::Result::Ok(val) => val,
            $crate::result::Result::Err(err) => {
                return $crate::result::Result::Err($crate::convert::From::from(err));
            }
        }
    };
}

/// Writes formatted data into a buffer.
///
/// This macro accepts a 'writer', a format string, and a list of arguments. Arguments will be
/// formatted according to the specified format string and the result will be passed to the writer.
/// The writer may be any value with a `write_fmt` method; generally this comes from an
/// implementation of either the [`fmt::Write`] or the [`io::Write`] trait. The macro
/// returns whatever the `write_fmt` method returns; commonly a [`fmt::Result`], or an
/// [`io::Result`].
///
/// See [`std::fmt`] for more information on the format string syntax.
///
/// [`std::fmt`]: ../std/fmt/index.html
/// [`fmt::Write`]: crate::fmt::Write
/// [`io::Write`]: ../std/io/trait.Write.html
/// [`fmt::Result`]: crate::fmt::Result
/// [`io::Result`]: ../std/io/type.Result.html
///
/// # Examples
///
/// ```
/// use std::io::Write;
///
/// fn main() -> std::io::Result<()> {
///     let mut w = Vec::new();
///     write!(&mut w, "test")?;
///     write!(&mut w, "formatted {}", "arguments")?;
///
///     assert_eq!(w, b"testformatted arguments");
///     Ok(())
/// }
/// ```
///
/// A module can import both `std::fmt::Write` and `std::io::Write` and call `write!` on objects
/// implementing either, as objects do not typically implement both. However, the module must
/// import the traits qualified so their names do not conflict:
///
/// ```
/// use std::fmt::Write as FmtWrite;
/// use std::io::Write as IoWrite;
///
/// fn main() -> Result<(), Box<dyn std::error::Error>> {
///     let mut s = String::new();
///     let mut v = Vec::new();
///
///     write!(&mut s, "{} {}", "abc", 123)?; // uses fmt::Write::write_fmt
///     write!(&mut v, "s = {:?}", s)?; // uses io::Write::write_fmt
///     assert_eq!(v, b"s = \"abc 123\"");
///     Ok(())
/// }
/// ```
///
/// Note: This macro can be used in `no_std` setups as well.
/// In a `no_std` setup you are responsible for the implementation details of the components.
///
/// ```no_run
/// # extern crate core;
/// use core::fmt::Write;
///
/// struct Example;
///
/// impl Write for Example {
///     fn write_str(&mut self, _s: &str) -> core::fmt::Result {
///          unimplemented!();
///     }
/// }
///
/// let mut m = Example{};
/// write!(&mut m, "Hello World").expect("Not written");
/// ```
#[macro_export]
#[stable(feature = "rust1", since = "1.0.0")]
macro_rules! write {
    ($dst:expr, $($arg:tt)*) => ($dst.write_fmt($crate::format_args!($($arg)*)))
}

/// Write formatted data into a buffer, with a newline appended.
///
/// On all platforms, the newline is the LINE FEED character (`\n`/`U+000A`) alone
/// (no additional CARRIAGE RETURN (`\r`/`U+000D`).
///
/// For more information, see [`write!`]. For information on the format string syntax, see
/// [`std::fmt`].
///
/// [`std::fmt`]: ../std/fmt/index.html
///
/// # Examples
///
/// ```
/// use std::io::{Write, Result};
///
/// fn main() -> Result<()> {
///     let mut w = Vec::new();
///     writeln!(&mut w)?;
///     writeln!(&mut w, "test")?;
///     writeln!(&mut w, "formatted {}", "arguments")?;
///
///     assert_eq!(&w[..], "\ntest\nformatted arguments\n".as_bytes());
///     Ok(())
/// }
/// ```
///
/// A module can import both `std::fmt::Write` and `std::io::Write` and call `write!` on objects
/// implementing either, as objects do not typically implement both. However, the module must
/// import the traits qualified so their names do not conflict:
///
/// ```
/// use std::fmt::Write as FmtWrite;
/// use std::io::Write as IoWrite;
///
/// fn main() -> Result<(), Box<dyn std::error::Error>> {
///     let mut s = String::new();
///     let mut v = Vec::new();
///
///     writeln!(&mut s, "{} {}", "abc", 123)?; // uses fmt::Write::write_fmt
///     writeln!(&mut v, "s = {:?}", s)?; // uses io::Write::write_fmt
///     assert_eq!(v, b"s = \"abc 123\\n\"\n");
///     Ok(())
/// }
/// ```
#[macro_export]
#[stable(feature = "rust1", since = "1.0.0")]
#[allow_internal_unstable(format_args_nl)]
macro_rules! writeln {
    ($dst:expr $(,)?) => (
        $crate::write!($dst, "\n")
    );
    ($dst:expr, $($arg:tt)*) => (
        $dst.write_fmt($crate::format_args_nl!($($arg)*))
    );
}

/// Indicates unreachable code.
///
/// This is useful any time that the compiler can't determine that some code is unreachable. For
/// example:
///
/// * Match arms with guard conditions.
/// * Loops that dynamically terminate.
/// * Iterators that dynamically terminate.
///
/// If the determination that the code is unreachable proves incorrect, the
/// program immediately terminates with a [`panic!`].
///
/// The unsafe counterpart of this macro is the [`unreachable_unchecked`] function, which
/// will cause undefined behavior if the code is reached.
///
/// [`unreachable_unchecked`]: crate::hint::unreachable_unchecked
///
/// # Panics
///
/// This will always [`panic!`].
///
/// # Examples
///
/// Match arms:
///
/// ```
/// # #[allow(dead_code)]
/// fn foo(x: Option<i32>) {
///     match x {
///         Some(n) if n >= 0 => println!("Some(Non-negative)"),
///         Some(n) if n <  0 => println!("Some(Negative)"),
///         Some(_)           => unreachable!(), // compile error if commented out
///         None              => println!("None")
///     }
/// }
/// ```
///
/// Iterators:
///
/// ```
/// # #[allow(dead_code)]
/// fn divide_by_three(x: u32) -> u32 { // one of the poorest implementations of x/3
///     for i in 0.. {
///         if 3*i < i { panic!("u32 overflow"); }
///         if x < 3*i { return i-1; }
///     }
///     unreachable!();
/// }
/// ```
#[macro_export]
#[stable(feature = "rust1", since = "1.0.0")]
macro_rules! unreachable {
    () => ({
        $crate::panic!("internal error: entered unreachable code")
    });
    ($msg:expr $(,)?) => ({
        $crate::unreachable!("{}", $msg)
    });
    ($fmt:expr, $($arg:tt)*) => ({
        $crate::panic!($crate::concat!("internal error: entered unreachable code: ", $fmt), $($arg)*)
    });
}

/// Indicates unimplemented code by panicking with a message of "not implemented".
///
/// This allows your code to type-check, which is useful if you are prototyping or
/// implementing a trait that requires multiple methods which you don't plan to use all of.
///
/// The difference between `unimplemented!` and [`todo!`] is that while `todo!`
/// conveys an intent of implementing the functionality later and the message is "not yet
/// implemented", `unimplemented!` makes no such claims. Its message is "not implemented".
/// Also some IDEs will mark `todo!`s.
///
/// # Panics
///
/// This will always [`panic!`] because `unimplemented!` is just a shorthand for `panic!` with a
/// fixed, specific message.
///
/// Like `panic!`, this macro has a second form for displaying custom values.
///
/// # Examples
///
/// Say we have a trait `Foo`:
{'fraction_non_alphanumeric': 0.19870435806831566, 'fraction_numerical': 0.0067608951707891635, 'mean_word_length': 2.538762920973658, 'pattern_counts': {'":': 0, '<': 35, '<?xml version=': 0, '>': 125, 'https://': 2, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
{'dir': 'git-commits-cleaned', 'id': '4714510', 'n_tokens_mistral': 13141, 'n_tokens_neox': 12988, 'n_words': 4116}