From 5d514f99b608eda79d72c69f20777b0028557d33 Mon Sep 17 00:00:00 2001
From: Diggory Hardy <git@dhardy.name>
Date: Mon, 16 Sep 2019 12:23:04 +0100
Subject: [PATCH] Make std feature imply alloc

---
 Cargo.toml                         |  2 +-
 src/base/alias.rs                  | 10 +++----
 src/base/construction.rs           |  2 +-
 src/base/conversion.rs             | 12 ++++----
 src/base/default_allocator.rs      | 20 ++++++-------
 src/base/edition.rs                | 46 +++++++++++++++---------------
 src/base/matrix_alga.rs            |  4 +--
 src/base/mod.rs                    |  4 +--
 src/lib.rs                         |  1 -
 src/linalg/permutation_sequence.rs |  4 +--
 10 files changed, 52 insertions(+), 53 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 47d4cf13..f239c4d0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -21,7 +21,7 @@ path = "src/lib.rs"
 
 [features]
 default         = [ "std", "rand_with_std" ]
-std             = [ "matrixmultiply", "alga/std" ]
+std             = [ "matrixmultiply", "alga/std", "alloc" ]
 # Since Cargo doesn't support multiplicitave features, use this to enable rand+std:
 rand_with_std   = [ "rand/std", "std", "rand_distr" ]
 stdweb          = [ "rand", "rand/stdweb" ]
diff --git a/src/base/alias.rs b/src/base/alias.rs
index a8925cf3..d28af20b 100644
--- a/src/base/alias.rs
+++ b/src/base/alias.rs
@@ -1,7 +1,7 @@
-#[cfg(any(feature = "alloc", feature = "std"))]
+#[cfg(feature = "alloc")]
 use crate::base::dimension::Dynamic;
 use crate::base::dimension::{U1, U2, U3, U4, U5, U6};
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 use crate::base::vec_storage::VecStorage;
 use crate::base::storage::Owned;
 use crate::base::Matrix;
@@ -24,7 +24,7 @@ pub type MatrixMN<N, R, C> = Matrix<N, R, C, Owned<N, R, C>>;
 pub type MatrixN<N, D> = MatrixMN<N, D, D>;
 
 /// A dynamically sized column-major matrix.
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 pub type DMatrix<N> = MatrixN<N, Dynamic>;
 
 /// A stack-allocated, column-major, 1x1 square matrix.
@@ -118,7 +118,7 @@ pub type Matrix6x5<N> = MatrixMN<N, U6, U5>;
  *
  */
 /// A dynamically sized column vector.
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 pub type DVector<N> = Matrix<N, Dynamic, U1, VecStorage<N, Dynamic, U1>>;
 
 /// A statically sized D-dimensional column vector.
@@ -145,7 +145,7 @@ pub type Vector6<N> = VectorN<N, U6>;
  *
  */
 /// A dynamically sized row vector.
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 pub type RowDVector<N> = Matrix<N, U1, Dynamic, VecStorage<N, U1, Dynamic>>;
 
 /// A statically sized D-dimensional row vector.
diff --git a/src/base/construction.rs b/src/base/construction.rs
index 04fda0d6..7ed3bef0 100644
--- a/src/base/construction.rs
+++ b/src/base/construction.rs
@@ -777,7 +777,7 @@ where
     }
 }
 
-#[cfg(feature = "arbitrary")]
+#[cfg(all(feature = "arbitrary", feature = "rand"))]
 impl<N, R, C> Arbitrary for MatrixMN<N, R, C>
 where
     R: Dim,
diff --git a/src/base/conversion.rs b/src/base/conversion.rs
index 4c5bb017..93a49fbb 100644
--- a/src/base/conversion.rs
+++ b/src/base/conversion.rs
@@ -14,11 +14,11 @@ use crate::base::constraint::{SameNumberOfColumns, SameNumberOfRows, ShapeConstr
 use crate::base::dimension::{
     Dim, DimName, U1, U10, U11, U12, U13, U14, U15, U16, U2, U3, U4, U5, U6, U7, U8, U9,
 };
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 use crate::base::dimension::Dynamic;
 use crate::base::iter::{MatrixIter, MatrixIterMut};
 use crate::base::storage::{ContiguousStorage, ContiguousStorageMut, Storage, StorageMut};
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 use crate::base::VecStorage;
 use crate::base::{DefaultAllocator, Matrix, ArrayStorage, MatrixMN, MatrixSlice, MatrixSliceMut, Scalar};
 
@@ -353,7 +353,7 @@ where
     }
 }
 
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 impl<'a, N, C, RStride, CStride> From<MatrixSlice<'a, N, Dynamic, C, RStride, CStride>>
     for Matrix<N, Dynamic, C, VecStorage<N, Dynamic, C>>
 where
@@ -367,7 +367,7 @@ where
     }
 }
 
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 impl<'a, N, R, RStride, CStride> From<MatrixSlice<'a, N, R, Dynamic, RStride, CStride>>
     for Matrix<N, R, Dynamic, VecStorage<N, R, Dynamic>>
 where
@@ -397,7 +397,7 @@ where
     }
 }
 
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 impl<'a, N, C, RStride, CStride> From<MatrixSliceMut<'a, N, Dynamic, C, RStride, CStride>>
     for Matrix<N, Dynamic, C, VecStorage<N, Dynamic, C>>
 where
@@ -411,7 +411,7 @@ where
     }
 }
 
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 impl<'a, N, R, RStride, CStride> From<MatrixSliceMut<'a, N, R, Dynamic, RStride, CStride>>
     for Matrix<N, R, Dynamic, VecStorage<N, R, Dynamic>>
 where
diff --git a/src/base/default_allocator.rs b/src/base/default_allocator.rs
index c07c8708..a04651aa 100644
--- a/src/base/default_allocator.rs
+++ b/src/base/default_allocator.rs
@@ -15,11 +15,11 @@ use generic_array::ArrayLength;
 use typenum::Prod;
 
 use crate::base::allocator::{Allocator, Reallocator};
-#[cfg(any(feature = "alloc", feature = "std"))]
+#[cfg(feature = "alloc")]
 use crate::base::dimension::Dynamic;
 use crate::base::dimension::{Dim, DimName};
 use crate::base::array_storage::ArrayStorage;
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 use crate::base::vec_storage::VecStorage;
 use crate::base::storage::{Storage, StorageMut};
 use crate::base::Scalar;
@@ -75,7 +75,7 @@ where
 
 // Dynamic - Static
 // Dynamic - Dynamic
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 impl<N: Scalar, C: Dim> Allocator<N, Dynamic, C> for DefaultAllocator {
     type Buffer = VecStorage<N, Dynamic, C>;
 
@@ -106,7 +106,7 @@ impl<N: Scalar, C: Dim> Allocator<N, Dynamic, C> for DefaultAllocator {
 }
 
 // Static - Dynamic
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 impl<N: Scalar, R: DimName> Allocator<N, R, Dynamic> for DefaultAllocator {
     type Buffer = VecStorage<N, R, Dynamic>;
 
@@ -172,7 +172,7 @@ where
 }
 
 // Static × Static -> Dynamic × Any
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 impl<N: Scalar, RFrom, CFrom, CTo> Reallocator<N, RFrom, CFrom, Dynamic, CTo> for DefaultAllocator
 where
     RFrom: DimName,
@@ -201,7 +201,7 @@ where
 }
 
 // Static × Static -> Static × Dynamic
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 impl<N: Scalar, RFrom, CFrom, RTo> Reallocator<N, RFrom, CFrom, RTo, Dynamic> for DefaultAllocator
 where
     RFrom: DimName,
@@ -230,7 +230,7 @@ where
 }
 
 // All conversion from a dynamic buffer to a dynamic buffer.
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 impl<N: Scalar, CFrom: Dim, CTo: Dim> Reallocator<N, Dynamic, CFrom, Dynamic, CTo>
     for DefaultAllocator
 {
@@ -246,7 +246,7 @@ impl<N: Scalar, CFrom: Dim, CTo: Dim> Reallocator<N, Dynamic, CFrom, Dynamic, CT
     }
 }
 
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 impl<N: Scalar, CFrom: Dim, RTo: DimName> Reallocator<N, Dynamic, CFrom, RTo, Dynamic>
     for DefaultAllocator
 {
@@ -262,7 +262,7 @@ impl<N: Scalar, CFrom: Dim, RTo: DimName> Reallocator<N, Dynamic, CFrom, RTo, Dy
     }
 }
 
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 impl<N: Scalar, RFrom: DimName, CTo: Dim> Reallocator<N, RFrom, Dynamic, Dynamic, CTo>
     for DefaultAllocator
 {
@@ -278,7 +278,7 @@ impl<N: Scalar, RFrom: DimName, CTo: Dim> Reallocator<N, RFrom, Dynamic, Dynamic
     }
 }
 
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 impl<N: Scalar, RFrom: DimName, RTo: DimName> Reallocator<N, RFrom, Dynamic, RTo, Dynamic>
     for DefaultAllocator
 {
diff --git a/src/base/edition.rs b/src/base/edition.rs
index e473246f..6db83490 100644
--- a/src/base/edition.rs
+++ b/src/base/edition.rs
@@ -1,20 +1,20 @@
 use num::{One, Zero};
 use std::cmp;
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 use std::iter::ExactSizeIterator;
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 use std::mem;
 use std::ptr;
 
 use crate::base::allocator::{Allocator, Reallocator};
 use crate::base::constraint::{DimEq, SameNumberOfColumns, SameNumberOfRows, ShapeConstraint};
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 use crate::base::dimension::Dynamic;
 use crate::base::dimension::{
     Dim, DimAdd, DimDiff, DimMin, DimMinimum, DimName, DimSub, DimSum, U1,
 };
 use crate::base::storage::{Storage, StorageMut};
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 use crate::base::DMatrix;
 use crate::base::{DefaultAllocator, Matrix, MatrixMN, RowVector, Scalar, Vector};
 
@@ -40,7 +40,7 @@ impl<N: Scalar + Zero, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
     }
 
     /// Creates a new matrix by extracting the given set of rows from `self`.
-    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg(feature = "alloc")]
     pub fn select_rows<'a, I>(&self, irows: I) -> MatrixMN<N, Dynamic, C>
     where
         I: IntoIterator<Item = &'a usize>,
@@ -72,7 +72,7 @@ impl<N: Scalar + Zero, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
     }
 
     /// Creates a new matrix by extracting the given set of columns from `self`.
-    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg(feature = "alloc")]
     pub fn select_columns<'a, I>(&self, icols: I) -> MatrixMN<N, R, Dynamic>
     where
         I: IntoIterator<Item = &'a usize>,
@@ -308,7 +308,7 @@ impl<N: Scalar, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
     }
 
     /// Removes all columns in `indices`   
-    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg(feature = "alloc")]
     pub fn remove_columns_at(self, indices: &[usize]) -> MatrixMN<N, R, Dynamic>
     where
         C: DimSub<Dynamic, Output = Dynamic>,
@@ -345,7 +345,7 @@ impl<N: Scalar, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
     }
 
     /// Removes all rows in `indices`   
-    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg(feature = "alloc")]
     pub fn remove_rows_at(self, indices: &[usize]) -> MatrixMN<N, Dynamic, C>
     where
         R: DimSub<Dynamic, Output = Dynamic>,
@@ -392,7 +392,7 @@ impl<N: Scalar, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
 
     /// Removes `n` consecutive columns from this matrix, starting with the `i`-th (included).
     #[inline]
-    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg(feature = "alloc")]
     pub fn remove_columns(self, i: usize, n: usize) -> MatrixMN<N, R, Dynamic>
     where
         C: DimSub<Dynamic, Output = Dynamic>,
@@ -475,7 +475,7 @@ impl<N: Scalar, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
 
     /// Removes `n` consecutive rows from this matrix, starting with the `i`-th (included).
     #[inline]
-    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg(feature = "alloc")]
     pub fn remove_rows(self, i: usize, n: usize) -> MatrixMN<N, Dynamic, C>
     where
         R: DimSub<Dynamic, Output = Dynamic>,
@@ -553,7 +553,7 @@ impl<N: Scalar, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
 
     /// Inserts `n` columns filled with `val` starting at the `i-th` position.
     #[inline]
-    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg(feature = "alloc")]
     pub fn insert_columns(self, i: usize, n: usize, val: N) -> MatrixMN<N, R, Dynamic>
     where
         C: DimAdd<Dynamic, Output = Dynamic>,
@@ -631,7 +631,7 @@ impl<N: Scalar, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
 
     /// Inserts `n` rows filled with `val` starting at the `i-th` position.
     #[inline]
-    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg(feature = "alloc")]
     pub fn insert_rows(self, i: usize, n: usize, val: N) -> MatrixMN<N, Dynamic, C>
     where
         R: DimAdd<Dynamic, Output = Dynamic>,
@@ -691,7 +691,7 @@ impl<N: Scalar, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
     ///
     /// The values are copied such that `self[(i, j)] == result[(i, j)]`. If the result has more
     /// rows and/or columns than `self`, then the extra rows or columns are filled with `val`.
-    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg(feature = "alloc")]
     pub fn resize(self, new_nrows: usize, new_ncols: usize, val: N) -> DMatrix<N>
     where DefaultAllocator: Reallocator<N, R, C, Dynamic, Dynamic> {
         self.resize_generic(Dynamic::new(new_nrows), Dynamic::new(new_ncols), val)
@@ -701,7 +701,7 @@ impl<N: Scalar, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
     ///
     /// The values are copied such that `self[(i, j)] == result[(i, j)]`. If the result has more
     /// rows than `self`, then the extra rows are filled with `val`.
-    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg(feature = "alloc")]
     pub fn resize_vertically(self, new_nrows: usize, val: N) -> MatrixMN<N, Dynamic, C>
     where DefaultAllocator: Reallocator<N, R, C, Dynamic, C> {
         let ncols = self.data.shape().1;
@@ -712,7 +712,7 @@ impl<N: Scalar, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
     ///
     /// The values are copied such that `self[(i, j)] == result[(i, j)]`. If the result has more
     /// columns than `self`, then the extra columns are filled with `val`.
-    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg(feature = "alloc")]
     pub fn resize_horizontally(self, new_ncols: usize, val: N) -> MatrixMN<N, R, Dynamic>
     where DefaultAllocator: Reallocator<N, R, C, R, Dynamic> {
         let nrows = self.data.shape().0;
@@ -796,7 +796,7 @@ impl<N: Scalar, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
     }
 }
 
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 impl<N: Scalar> DMatrix<N> {
     /// Resizes this matrix in-place.
     ///
@@ -813,7 +813,7 @@ impl<N: Scalar> DMatrix<N> {
     }
 }
 
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 impl<N: Scalar, C: Dim> MatrixMN<N, Dynamic, C>
 where DefaultAllocator: Allocator<N, Dynamic, C>
 {
@@ -823,7 +823,7 @@ where DefaultAllocator: Allocator<N, Dynamic, C>
     /// rows than `self`, then the extra rows are filled with `val`.
     ///
     /// Defined only for owned matrices with a dynamic number of rows (for example, `DVector`).
-    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg(feature = "alloc")]
     pub fn resize_vertically_mut(&mut self, new_nrows: usize, val: N)
     where DefaultAllocator: Reallocator<N, Dynamic, C, Dynamic, C> {
         let placeholder =
@@ -834,7 +834,7 @@ where DefaultAllocator: Allocator<N, Dynamic, C>
     }
 }
 
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 impl<N: Scalar, R: Dim> MatrixMN<N, R, Dynamic>
 where DefaultAllocator: Allocator<N, R, Dynamic>
 {
@@ -844,7 +844,7 @@ where DefaultAllocator: Allocator<N, R, Dynamic>
     /// columns than `self`, then the extra columns are filled with `val`.
     ///
     /// Defined only for owned matrices with a dynamic number of columns (for example, `DVector`).
-    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cfg(feature = "alloc")]
     pub fn resize_horizontally_mut(&mut self, new_ncols: usize, val: N)
     where DefaultAllocator: Reallocator<N, R, Dynamic, R, Dynamic> {
         let placeholder =
@@ -935,7 +935,7 @@ unsafe fn extend_rows<N: Scalar>(
 
 /// Extend the number of columns of the `Matrix` with elements from
 /// a given iterator.
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 impl<N, R, S> Extend<N> for Matrix<N, R, Dynamic, S>
 where
     N: Scalar,
@@ -983,7 +983,7 @@ where
 
 /// Extend the number of rows of the `Vector` with elements from
 /// a given iterator.
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 impl<N, S> Extend<N> for Matrix<N, Dynamic, U1, S>
 where
     N: Scalar,
@@ -1004,7 +1004,7 @@ where
     }
 }
 
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 impl<N, R, S, RV, SV> Extend<Vector<N, RV, SV>> for Matrix<N, R, Dynamic, S>
 where
     N: Scalar,
diff --git a/src/base/matrix_alga.rs b/src/base/matrix_alga.rs
index ac6aced7..5419f02d 100644
--- a/src/base/matrix_alga.rs
+++ b/src/base/matrix_alga.rs
@@ -285,7 +285,7 @@ where DefaultAllocator: Allocator<N, R, C>
                 }
             }
             _ => {
-                #[cfg(any(feature = "std", feature = "alloc"))]
+                #[cfg(feature = "alloc")]
                 {
                     // XXX: use a GenericArray instead.
                     let mut known_basis = Vec::new();
@@ -310,7 +310,7 @@ where DefaultAllocator: Allocator<N, R, C>
                         }
                     }
                 }
-                #[cfg(all(not(feature = "std"), not(feature = "alloc")))]
+                #[cfg(not(feature = "alloc"))]
                 {
                     panic!("Cannot compute the orthogonal subspace basis of a vector with a dimension greater than 3 \
                             if #![no_std] is enabled and the 'alloc' feature is not enabled.")
diff --git a/src/base/mod.rs b/src/base/mod.rs
index 0ec6311c..139e560b 100644
--- a/src/base/mod.rs
+++ b/src/base/mod.rs
@@ -23,7 +23,7 @@ mod matrix;
 mod matrix_alga;
 mod array_storage;
 mod matrix_slice;
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 mod vec_storage;
 mod properties;
 mod scalar;
@@ -47,5 +47,5 @@ pub use self::alias::*;
 pub use self::alias_slice::*;
 pub use self::array_storage::*;
 pub use self::matrix_slice::*;
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 pub use self::vec_storage::*;
diff --git a/src/lib.rs b/src/lib.rs
index 08dfcbe2..139b53d2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -87,7 +87,6 @@ an optimized set of tools for computer graphics and physics. Those features incl
     html_root_url = "https://nalgebra.org/rustdoc"
 )]
 #![cfg_attr(not(feature = "std"), no_std)]
-#![cfg_attr(all(feature = "alloc", not(feature = "std")), feature(alloc))]
 
 #[macro_use]
 extern crate approx;
diff --git a/src/linalg/permutation_sequence.rs b/src/linalg/permutation_sequence.rs
index ce493905..3202e0b2 100644
--- a/src/linalg/permutation_sequence.rs
+++ b/src/linalg/permutation_sequence.rs
@@ -6,7 +6,7 @@ use num::One;
 
 use crate::allocator::Allocator;
 use crate::base::{DefaultAllocator, Matrix, Scalar, VectorN};
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 use crate::dimension::Dynamic;
 use crate::dimension::{Dim, DimName, U1};
 use crate::storage::StorageMut;
@@ -51,7 +51,7 @@ where DefaultAllocator: Allocator<(usize, usize), D>
     }
 }
 
-#[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 impl PermutationSequence<Dynamic>
 where DefaultAllocator: Allocator<(usize, usize), Dynamic>
 {