IndexMap is a hash table where the iteration order of the key-value
pairs is independent of the hash values of the keys.
IndexSet is a corresponding hash set using the same implementation and
with similar properties.
- The ordering semantics (see their documentation for details)
- Sorting methods and the [
- The [
Equivalent] trait, which offers more flexible equality definitions between borrowed and owned versions of keys.
- The [
MutableKeys][map::MutableKeys] trait, which gives opt-in mutable access to hash map keys.
This version of indexmap requires Rust 1.18 or later, or 1.32+ for
development builds, and Rust 1.36+ for using with
The indexmap 1.x release series will use a carefully considered version upgrade policy, where in a later 1.x version, we will raise the minimum required Rust version.
No Standard Library Targets
From Rust 1.36, this crate supports being built without
alloc instead. This is enabled automatically when it is detected that
std is not available. There is no crate feature to enable/disable to
trigger this. It can be tested by building for a std-less target.
- Creating maps and sets using [
new][IndexMap::new] and [
with_capacity][IndexMap::with_capacity] is unavailable without
with_capacity_and_hasher][IndexMap::with_capacity_and_hasher] instead. A no-std compatible hasher will be needed as well, for example from the crate
- Macros [
indexmap!] and [
indexset!] are unavailable without