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|
// implements the unary operator "op &T"
// based on "op T" where T is expected to be `Copy`able
macro_rules! forward_ref_unop {
(impl const $imp:ident, $method:ident for $t:ty) => {
forward_ref_unop!(impl const $imp, $method for $t,
#[stable(feature = "rust1", since = "1.0.0")]);
};
// Equivalent to the non-const version, with the addition of `rustc_const_unstable`
(impl const $imp:ident, $method:ident for $t:ty, #[$attr:meta]) => {
#[$attr]
#[rustc_const_unstable(feature = "const_ops", issue = "90080")]
impl const $imp for &$t {
type Output = <$t as $imp>::Output;
#[inline]
fn $method(self) -> <$t as $imp>::Output {
$imp::$method(*self)
}
}
};
(impl $imp:ident, $method:ident for $t:ty, #[$attr:meta]) => {
#[$attr]
impl $imp for &$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 const $imp:ident, $method:ident for $t:ty, $u:ty) => {
forward_ref_binop!(impl const $imp, $method for $t, $u,
#[stable(feature = "rust1", since = "1.0.0")]);
};
// Equivalent to the non-const version, with the addition of `rustc_const_unstable`
(impl const $imp:ident, $method:ident for $t:ty, $u:ty, #[$attr:meta]) => {
#[$attr]
#[rustc_const_unstable(feature = "const_ops", issue = "90080")]
impl<'a> const $imp<$u> for &'a $t {
type Output = <$t as $imp<$u>>::Output;
#[inline]
fn $method(self, other: $u) -> <$t as $imp<$u>>::Output {
$imp::$method(*self, other)
}
}
#[$attr]
#[rustc_const_unstable(feature = "const_ops", issue = "90080")]
impl const $imp<&$u> for $t {
type Output = <$t as $imp<$u>>::Output;
#[inline]
fn $method(self, other: &$u) -> <$t as $imp<$u>>::Output {
$imp::$method(self, *other)
}
}
#[$attr]
#[rustc_const_unstable(feature = "const_ops", issue = "90080")]
impl const $imp<&$u> for &$t {
type Output = <$t as $imp<$u>>::Output;
#[inline]
fn $method(self, other: &$u) -> <$t as $imp<$u>>::Output {
$imp::$method(*self, *other)
}
}
};
(impl $imp:ident, $method:ident for $t:ty, $u:ty, #[$attr:meta]) => {
#[$attr]
impl<'a> $imp<$u> for &'a $t {
type Output = <$t as $imp<$u>>::Output;
#[inline]
fn $method(self, other: $u) -> <$t as $imp<$u>>::Output {
$imp::$method(*self, other)
}
}
#[$attr]
impl $imp<&$u> for $t {
type Output = <$t as $imp<$u>>::Output;
#[inline]
fn $method(self, other: &$u) -> <$t as $imp<$u>>::Output {
$imp::$method(self, *other)
}
}
#[$attr]
impl $imp<&$u> for &$t {
type Output = <$t as $imp<$u>>::Output;
#[inline]
fn $method(self, other: &$u) -> <$t as $imp<$u>>::Output {
$imp::$method(*self, *other)
}
}
}
}
// 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) => {
forward_ref_op_assign!(impl $imp, $method for $t, $u,
#[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]);
};
(impl const $imp:ident, $method:ident for $t:ty, $u:ty) => {
forward_ref_op_assign!(impl const $imp, $method for $t, $u,
#[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]);
};
// Equivalent to the non-const version, with the addition of `rustc_const_unstable`
(impl const $imp:ident, $method:ident for $t:ty, $u:ty, #[$attr:meta]) => {
#[$attr]
#[rustc_const_unstable(feature = "const_ops", issue = "90080")]
impl const $imp<&$u> for $t {
#[inline]
fn $method(&mut self, other: &$u) {
$imp::$method(self, *other);
}
}
};
(impl $imp:ident, $method:ident for $t:ty, $u:ty, #[$attr:meta]) => {
#[$attr]
impl $imp<&$u> for $t {
#[inline]
fn $method(&mut self, other: &$u) {
$imp::$method(self, *other);
}
}
}
}
/// Create a zero-size type similar to a closure type, but named.
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, )*))
}
}
)+
}
}
/// A macro for defining `#[cfg]` if-else statements.
///
/// `cfg_if` is similar to the `if/elif` C preprocessor macro by allowing definition of a cascade
/// of `#[cfg]` cases, emitting the implementation which matches first.
///
/// This allows you to conveniently provide a long list `#[cfg]`'d blocks of code without having to
/// rewrite each clause multiple times.
///
/// # Example
///
/// ```ignore(cannot-test-this-because-non-exported-macro)
/// cfg_if! {
/// if #[cfg(unix)] {
/// fn foo() { /* unix specific functionality */ }
/// } else if #[cfg(target_pointer_width = "32")] {
/// fn foo() { /* non-unix, 32-bit functionality */ }
/// } else {
/// fn foo() { /* fallback implementation */ }
/// }
/// }
///
/// # fn main() {}
/// ```
// This is a copy of `cfg_if!` from the `cfg_if` crate.
// The recursive invocations should use $crate if this is ever exported.
macro_rules! cfg_if {
// match if/else chains with a final `else`
(
$(
if #[cfg( $i_meta:meta )] { $( $i_tokens:tt )* }
) else+
else { $( $e_tokens:tt )* }
) => {
cfg_if! {
@__items () ;
$(
(( $i_meta ) ( $( $i_tokens )* )) ,
)+
(() ( $( $e_tokens )* )) ,
}
};
// Internal and recursive macro to emit all the items
//
// Collects all the previous cfgs in a list at the beginning, so they can be
// negated. After the semicolon is all the remaining items.
(@__items ( $( $_:meta , )* ) ; ) => {};
(
@__items ( $( $no:meta , )* ) ;
(( $( $yes:meta )? ) ( $( $tokens:tt )* )) ,
$( $rest:tt , )*
) => {
// Emit all items within one block, applying an appropriate #[cfg]. The
// #[cfg] will require all `$yes` matchers specified and must also negate
// all previous matchers.
#[cfg(all(
$( $yes , )?
not(any( $( $no ),* ))
))]
cfg_if! { @__identity $( $tokens )* }
// Recurse to emit all other items in `$rest`, and when we do so add all
// our `$yes` matchers to the list of `$no` matchers as future emissions
// will have to negate everything we just matched as well.
cfg_if! {
@__items ( $( $no , )* $( $yes , )? ) ;
$( $rest , )*
}
};
// Internal macro to make __apply work out right for different match types,
// because of how macros match/expand stuff.
(@__identity $( $tokens:tt )* ) => {
$( $tokens )*
};
}
|
