1 files changed, 56 insertions, 0 deletions
diff --git a/src/compat.rs b/src/compat.rs
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--- /dev/null
+++ b/src/compat.rs
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+//! `no_std` compatibility
+
+// If we depend on `ahash`, use its hasher.
+#[cfg(feature = "ahash")]
+pub use ahash::RandomState;
+
+// Use the `std` hasher if we don’t depend on `ahash` but do depend on
+// `std`.
+#[cfg(all(not(feature = "ahash"), feature = "std"))]
+pub use std::collections::hash_map::RandomState;
+
+// If we depend on neither `ahash` nor `std` then it’s an error.
+#[cfg(not(any(feature = "ahash", feature = "std")))]
+compile_error!("weak-table: no_std requires that you enable the `ahash` feature.");
+
+// If we depend on `std`, alias `lib` to `std`.
+#[cfg(feature = "std")]
+mod lib {
+    extern crate std;
+    pub use std::*;
+}
+
+// Otherwise, we are `no_std`, so alias `lib` to `alloc`.
+#[cfg(not(feature = "std"))]
+mod lib {
+    extern crate alloc;
+    pub use alloc::*;
+}
+
+// Stuff from `std`/`alloc` that we use often.
+pub use lib::{
+    boxed::Box,
+    rc,
+    slice,
+    string::String,
+    sync,
+    vec::{self, Vec},
+};
+
+// Stuff from `core` that we use often:
+pub use core::{
+    borrow::Borrow,
+    cmp::max,
+    hash::{BuildHasher, Hash, Hasher},
+    iter::{self, FromIterator},
+    fmt::{self, Debug, Formatter},
+    mem,
+    ops::{self, Deref, Index, IndexMut},
+};
+
+// When testing, we need the `eprintln` macro from `std`:
+#[cfg(test)]
+extern crate std;
+
+#[cfg(test)]
+pub use std::eprintln;