🚸 Don't make users declare alloc crate

Author: zeenix

src/boxed.rs

@@ -11,8 +11,6 @@
 //! ```
 //! use mayheap::{box_pool, boxed::{BoxPool, Box}};
 //!
-//! extern crate alloc;
-//!
 //! // Create a pool for u32 type with a capacity of 10.
 //! box_pool!(MyBoxPool: u32, 2);
 //!
@@ -93,14 +91,16 @@ macro_rules! box_pool {
 
         impl $crate::boxed::BoxPool for $name {
             type Data = $ty;
-            type BoxedValue = alloc::boxed::Box<$ty>;
+            type BoxedValue = $crate::reexports::alloc::boxed::Box<$ty>;
 
             fn alloc(&self, value: Self::Data) -> Result<$crate::boxed::Box<Self>, Self::Data> {
-                Ok($crate::boxed::Box::new(alloc::boxed::Box::new(value)))
+                Ok($crate::boxed::Box::new(
+                    $crate::reexports::alloc::boxed::Box::new(value),
+                ))
             }
         }
 
-        $crate::paste::paste! {
+        $crate::reexports::paste::paste! {
             // Let's use the $capacity variable so callers don't get "unused const" warnings.
             #[allow(non_upper_case_globals, dead_code)]
             const [<__dummy__ $name>]: () = {
@@ -115,7 +115,7 @@ macro_rules! box_pool {
 #[macro_export]
 macro_rules! box_pool {
     ($name:ident: $ty:ty, $capacity:expr) => {
-        $crate::paste::paste! {
+        $crate::reexports::paste::paste! {
             heapless::box_pool!([<$name Pool>]: $ty);
 
             #[derive(Debug, Clone, PartialEq, Eq)]

src/lib.rs

@@ -12,12 +12,13 @@
 #[cfg(all(not(feature = "alloc"), not(feature = "heapless")))]
 compile_error!("Either the `alloc` or `heapless` feature must be enabled");
 
-#[cfg(feature = "alloc")]
-extern crate alloc;
-
-// Re-export `paste` for the macros.
+// Re-exports for the macros.
 #[doc(hidden)]
-pub use paste;
+pub mod reexports {
+    #[cfg(feature = "alloc")]
+    pub extern crate alloc;
+    pub use paste;
+}
 
 pub mod vec;
 pub use vec::Vec;

src/string.rs

@@ -5,7 +5,7 @@ use core::{cmp::Ordering, fmt, hash, iter, ops, str};
 use crate::Vec;
 
 #[cfg(feature = "alloc")]
-type Inner<const N: usize> = alloc::string::String;
+type Inner<const N: usize> = crate::reexports::alloc::string::String;
 #[cfg(not(feature = "alloc"))]
 type Inner<const N: usize> = heapless::String<N>;
 
@@ -357,7 +357,9 @@ macro_rules! impl_try_from_num {
             fn try_from(s: $num) -> Result<Self, Self::Error> {
                 #[cfg(feature = "alloc")]
                 {
-                    Ok(Self(alloc::string::ToString::to_string(&s)))
+                    Ok(Self(crate::reexports::alloc::string::ToString::to_string(
+                        &s,
+                    )))
                 }
                 #[cfg(not(feature = "alloc"))]
                 {

src/vec.rs

@@ -5,7 +5,7 @@
 use core::{cmp::Ordering, fmt, hash, iter::FromIterator, ops, slice};
 
 #[cfg(feature = "alloc")]
-pub(crate) type Inner<T, const N: usize> = alloc::vec::Vec<T>;
+pub(crate) type Inner<T, const N: usize> = crate::reexports::alloc::vec::Vec<T>;
 #[cfg(not(feature = "alloc"))]
 pub(crate) type Inner<T, const N: usize> = heapless::Vec<T, N>;
 
@@ -437,7 +437,7 @@ impl<T, const N: usize> FromIterator<T> for Vec<T, N> {
 #[derive(Clone, Debug)]
 pub struct IntoIter<T, const N: usize> {
     #[cfg(feature = "alloc")]
-    iter: alloc::vec::IntoIter<T>,
+    iter: crate::reexports::alloc::vec::IntoIter<T>,
     // FIXME: Once the fix for https://github.com/rust-embedded/heapless/issues/530 is released. We
     // can turn this into a wrapper around `heapless::vec::IntoIter`.
     #[cfg(not(feature = "alloc"))]