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-rw-r--r--vendor/hashbrown-0.12.3/src/macros.rs70
1 files changed, 70 insertions, 0 deletions
diff --git a/vendor/hashbrown-0.12.3/src/macros.rs b/vendor/hashbrown-0.12.3/src/macros.rs
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+++ b/vendor/hashbrown-0.12.3/src/macros.rs
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+// See the cfg-if crate.
+#[allow(unused_macro_rules)]
+macro_rules! cfg_if {
+ // match if/else chains with a final `else`
+ ($(
+ if #[cfg($($meta:meta),*)] { $($it:item)* }
+ ) else * else {
+ $($it2:item)*
+ }) => {
+ cfg_if! {
+ @__items
+ () ;
+ $( ( ($($meta),*) ($($it)*) ), )*
+ ( () ($($it2)*) ),
+ }
+ };
+
+ // match if/else chains lacking a final `else`
+ (
+ if #[cfg($($i_met:meta),*)] { $($i_it:item)* }
+ $(
+ else if #[cfg($($e_met:meta),*)] { $($e_it:item)* }
+ )*
+ ) => {
+ cfg_if! {
+ @__items
+ () ;
+ ( ($($i_met),*) ($($i_it)*) ),
+ $( ( ($($e_met),*) ($($e_it)*) ), )*
+ ( () () ),
+ }
+ };
+
+ // Internal and recursive macro to emit all the items
+ //
+ // Collects all the negated cfgs in a list at the beginning and after the
+ // semicolon is all the remaining items
+ (@__items ($($not:meta,)*) ; ) => {};
+ (@__items ($($not:meta,)*) ; ( ($($m:meta),*) ($($it:item)*) ), $($rest:tt)*) => {
+ // Emit all items within one block, applying an approprate #[cfg]. The
+ // #[cfg] will require all `$m` matchers specified and must also negate
+ // all previous matchers.
+ cfg_if! { @__apply cfg(all($($m,)* not(any($($not),*)))), $($it)* }
+
+ // Recurse to emit all other items in `$rest`, and when we do so add all
+ // our `$m` matchers to the list of `$not` matchers as future emissions
+ // will have to negate everything we just matched as well.
+ cfg_if! { @__items ($($not,)* $($m,)*) ; $($rest)* }
+ };
+
+ // Internal macro to Apply a cfg attribute to a list of items
+ (@__apply $m:meta, $($it:item)*) => {
+ $(#[$m] $it)*
+ };
+}
+
+// Helper macro for specialization. This also helps avoid parse errors if the
+// default fn syntax for specialization changes in the future.
+#[cfg(feature = "nightly")]
+macro_rules! default_fn {
+ (#[$($a:tt)*] $($tt:tt)*) => {
+ #[$($a)*] default $($tt)*
+ }
+}
+#[cfg(not(feature = "nightly"))]
+macro_rules! default_fn {
+ ($($tt:tt)*) => {
+ $($tt)*
+ }
+}