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#[cfg(feature = "std")]
#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
#[macro_export]
/// Create an [`IndexMap`][crate::IndexMap] from a list of key-value pairs
///
/// ## Example
///
/// ```
/// use indexmap::indexmap;
///
/// let map = indexmap!{
/// "a" => 1,
/// "b" => 2,
/// };
/// assert_eq!(map["a"], 1);
/// assert_eq!(map["b"], 2);
/// assert_eq!(map.get("c"), None);
///
/// // "a" is the first key
/// assert_eq!(map.keys().next(), Some(&"a"));
/// ```
macro_rules! indexmap {
($($key:expr => $value:expr,)+) => { $crate::indexmap!($($key => $value),+) };
($($key:expr => $value:expr),*) => {
{
// Note: `stringify!($key)` is just here to consume the repetition,
// but we throw away that string literal during constant evaluation.
const CAP: usize = <[()]>::len(&[$({ stringify!($key); }),*]);
let mut map = $crate::IndexMap::with_capacity(CAP);
$(
map.insert($key, $value);
)*
map
}
};
}
#[cfg(feature = "std")]
#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
#[macro_export]
/// Create an [`IndexSet`][crate::IndexSet] from a list of values
///
/// ## Example
///
/// ```
/// use indexmap::indexset;
///
/// let set = indexset!{
/// "a",
/// "b",
/// };
/// assert!(set.contains("a"));
/// assert!(set.contains("b"));
/// assert!(!set.contains("c"));
///
/// // "a" is the first value
/// assert_eq!(set.iter().next(), Some(&"a"));
/// ```
macro_rules! indexset {
($($value:expr,)+) => { $crate::indexset!($($value),+) };
($($value:expr),*) => {
{
// Note: `stringify!($value)` is just here to consume the repetition,
// but we throw away that string literal during constant evaluation.
const CAP: usize = <[()]>::len(&[$({ stringify!($value); }),*]);
let mut set = $crate::IndexSet::with_capacity(CAP);
$(
set.insert($value);
)*
set
}
};
}
// generate all the Iterator methods by just forwarding to the underlying
// self.iter and mapping its element.
macro_rules! iterator_methods {
// $map_elt is the mapping function from the underlying iterator's element
// same mapping function for both options and iterators
($map_elt:expr) => {
fn next(&mut self) -> Option<Self::Item> {
self.iter.next().map($map_elt)
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
fn count(self) -> usize {
self.iter.len()
}
fn nth(&mut self, n: usize) -> Option<Self::Item> {
self.iter.nth(n).map($map_elt)
}
fn last(mut self) -> Option<Self::Item> {
self.next_back()
}
fn collect<C>(self) -> C
where
C: FromIterator<Self::Item>,
{
// NB: forwarding this directly to standard iterators will
// allow it to leverage unstable traits like `TrustedLen`.
self.iter.map($map_elt).collect()
}
};
}
macro_rules! double_ended_iterator_methods {
// $map_elt is the mapping function from the underlying iterator's element
// same mapping function for both options and iterators
($map_elt:expr) => {
fn next_back(&mut self) -> Option<Self::Item> {
self.iter.next_back().map($map_elt)
}
fn nth_back(&mut self, n: usize) -> Option<Self::Item> {
self.iter.nth_back(n).map($map_elt)
}
};
}
// generate `ParallelIterator` methods by just forwarding to the underlying
// self.entries and mapping its elements.
#[cfg(any(feature = "rayon", feature = "rustc-rayon"))]
macro_rules! parallel_iterator_methods {
// $map_elt is the mapping function from the underlying iterator's element
($map_elt:expr) => {
fn drive_unindexed<C>(self, consumer: C) -> C::Result
where
C: UnindexedConsumer<Self::Item>,
{
self.entries
.into_par_iter()
.map($map_elt)
.drive_unindexed(consumer)
}
// NB: This allows indexed collection, e.g. directly into a `Vec`, but the
// underlying iterator must really be indexed. We should remove this if we
// start having tombstones that must be filtered out.
fn opt_len(&self) -> Option<usize> {
Some(self.entries.len())
}
};
}
// generate `IndexedParallelIterator` methods by just forwarding to the underlying
// self.entries and mapping its elements.
#[cfg(any(feature = "rayon", feature = "rustc-rayon"))]
macro_rules! indexed_parallel_iterator_methods {
// $map_elt is the mapping function from the underlying iterator's element
($map_elt:expr) => {
fn drive<C>(self, consumer: C) -> C::Result
where
C: Consumer<Self::Item>,
{
self.entries.into_par_iter().map($map_elt).drive(consumer)
}
fn len(&self) -> usize {
self.entries.len()
}
fn with_producer<CB>(self, callback: CB) -> CB::Output
where
CB: ProducerCallback<Self::Item>,
{
self.entries
.into_par_iter()
.map($map_elt)
.with_producer(callback)
}
};
}