// implements the unary operator "op &T"

// based on "op T" where T is expected to be `Copy`able

macro_rules! forward_ref_unop {

    (impl $imp:ident, $method:ident for $t:ty, $(#[$attr:meta])+) => {

        $(#[$attr])+

        impl const $imp for &$t {

            type Output = <$t as $imp>::Output;

            #[inline]

            fn $method(self) -> <$t as $imp>::Output {

                $imp::$method(*self)

            }

        }

    }

}

// implements binary operators "&T op U", "T op &U", "&T op &U"

// based on "T op U" where T and U are expected to be `Copy`able

macro_rules! forward_ref_binop {

    (impl $imp:ident, $method:ident for $t:ty, $u:ty, $(#[$attr:meta])+) => {

        $(#[$attr])+

        impl const $imp<$u> for &$t {

            type Output = <$t as $imp<$u>>::Output;

            #[inline]

            #[track_caller]

        }

        $(#[$attr])+

        impl const $imp<&$u> for $t {

            type Output = <$t as $imp<$u>>::Output;

            #[inline]

            #[track_caller]

            fn $method(self, other: &$u) -> <$t as $imp<$u>>::Output {

                $imp::$method(self, *other)

            }

        }

        $(#[$attr])+

        impl const $imp<&$u> for &$t {

            type Output = <$t as $imp<$u>>::Output;

            #[inline]

            #[track_caller]

        }

    }

}

// implements "T op= &U", based on "T op= U"

// where U is expected to be `Copy`able

macro_rules! forward_ref_op_assign {

    (impl $imp:ident, $method:ident for $t:ty, $u:ty, $(#[$attr:meta])+) => {

        $(#[$attr])+

        impl const $imp<&$u> for $t {

            #[inline]

            #[track_caller]

        }

    }

}

/// Creates a zero-size type similar to a closure type, but named.

#[cfg(not(feature = "ferrocene_certified"))]

macro_rules! impl_fn_for_zst {

    ($(

        $( #[$attr: meta] )*

        struct $Name: ident impl$( <$( $lifetime : lifetime ),+> )? Fn =

            |$( $arg: ident: $ArgTy: ty ),*| -> $ReturnTy: ty

            $body: block;

    )+) => {

        $(

            $( #[$attr] )*

            struct $Name;

            impl $( <$( $lifetime ),+> )? Fn<($( $ArgTy, )*)> for $Name {

                #[inline]

                extern "rust-call" fn call(&self, ($( $arg, )*): ($( $ArgTy, )*)) -> $ReturnTy {

                    $body

                }

            }

            impl $( <$( $lifetime ),+> )? FnMut<($( $ArgTy, )*)> for $Name {

                #[inline]

                extern "rust-call" fn call_mut(

                    &mut self,

                    ($( $arg, )*): ($( $ArgTy, )*)

                ) -> $ReturnTy {

                    Fn::call(&*self, ($( $arg, )*))

                }

            }

            impl $( <$( $lifetime ),+> )? FnOnce<($( $ArgTy, )*)> for $Name {

                type Output = $ReturnTy;

                #[inline]

                extern "rust-call" fn call_once(self, ($( $arg, )*): ($( $ArgTy, )*)) -> $ReturnTy {

                    Fn::call(&self, ($( $arg, )*))

                }

            }

        )+

    }

}