Make rand optional

Tests pass with default features (rand_with_std)
Tests pass with std only, with --tests restriction (doc tests fail)

Cargo.toml

@@ -20,9 +20,11 @@ name = "nalgebra"
 path = "src/lib.rs"
 
 [features]
-default         = [ "std" ]
+default         = [ "std", "rand_with_std" ]
-std             = [ "matrixmultiply", "rand/std", "alga/std", "rand_distr" ]
+std             = [ "matrixmultiply", "alga/std" ]
-stdweb          = [ "rand/stdweb" ]
+# 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" ]
 arbitrary       = [ "quickcheck" ]
 serde-serialize = [ "serde", "serde_derive", "num-complex/serde" ]
 abomonation-serialize = [ "abomonation" ]
@@ -34,7 +36,7 @@ io = [ "pest", "pest_derive" ]
 [dependencies]
 typenum        = "1.10"
 generic-array  = "0.12"
-rand           = { version = "0.7", default-features = false }
+rand           = { version = "0.7", optional = true, default-features = false }
 rand_distr     = { version = "0.2", optional = true }
 num-traits     = { version = "0.2", default-features = false }
 num-complex    = { version = "0.2", default-features = false }

ci/test.sh

@@ -5,6 +5,7 @@ set -ev
 if [ -z "$NO_STD" ]; then
     if [ -z "$LAPACK" ]; then
         cargo test --verbose --no-default-features --lib;
+        cargo test --verbose --no-default-features --features "std" --tests;
         cargo test --verbose;
         cargo test --verbose "arbitrary";
         cargo test --verbose --all-features;

src/base/construction.rs

@@ -4,14 +4,12 @@ use crate::base::storage::Owned;
 use quickcheck::{Arbitrary, Gen};
 
 use num::{Bounded, One, Zero};
-use rand::distributions::{Distribution, Standard};
+#[cfg(feature = "rand")]
-use rand::Rng;
+use rand::{Rng, distributions::{Distribution, Standard}};
-#[cfg(feature = "std")]
-use rand_distr::StandardNormal;
 use std::iter;
 use typenum::{self, Cmp, Greater};
 
-#[cfg(feature = "std")]
+#[cfg(feature = "rand_distr")]
 use alga::general::RealField;
 use alga::general::{ClosedAdd, ClosedMul};
 
@@ -240,7 +238,7 @@ where DefaultAllocator: Allocator<N, R, C>
 
     /// Creates a matrix filled with random values.
     #[inline]
-    #[cfg(feature = "std")]
+    #[cfg(feature = "rand_with_std")]
     pub fn new_random_generic(nrows: R, ncols: C) -> Self
     where Standard: Distribution<N> {
         let mut rng = rand::thread_rng();
@@ -248,6 +246,7 @@ where DefaultAllocator: Allocator<N, R, C>
     }
 
     /// Creates a matrix filled with random values from the given distribution.
+    #[cfg(feature = "rand")]
     #[inline]
     pub fn from_distribution_generic<Distr: Distribution<N> + ?Sized, G: Rng + ?Sized>(
         nrows: R,
@@ -548,6 +547,7 @@ macro_rules! impl_constructors(
             }
 
             /// Creates a matrix or vector filled with random values from the given distribution.
+            #[cfg(feature = "rand")]
             #[inline]
             pub fn from_distribution<Distr: Distribution<N> + ?Sized, G: Rng + ?Sized>(
                 $($args: usize,)*
@@ -558,6 +558,7 @@ macro_rules! impl_constructors(
             }
         }
 
+        #[cfg(feature = "rand")]
         impl<N: Scalar, $($DimIdent: $DimBound, )*> MatrixMN<N $(, $Dims)*>
             where
             DefaultAllocator: Allocator<N $(, $Dims)*>,
@@ -565,7 +566,7 @@ macro_rules! impl_constructors(
 
             /// Creates a matrix filled with random values.
             #[inline]
-            #[cfg(feature = "std")]
+            #[cfg(feature = "rand_with_std")]
             pub fn new_random($($args: usize),*) -> Self {
                 Self::new_random_generic($($gargs),*)
             }
@@ -761,6 +762,7 @@ where
     }
 }
 
+#[cfg(feature = "rand")]
 impl<N: Scalar, R: Dim, C: Dim> Distribution<MatrixMN<N, R, C>> for Standard
 where
     DefaultAllocator: Allocator<N, R, C>,
@@ -796,11 +798,11 @@ where
 }
 
 // TODO(specialization): faster impls possible for D≤4 (see rand_distr::{UnitCircle, UnitSphere})
-#[cfg(feature = "std")]
+#[cfg(feature = "rand_distr")]
 impl<N: RealField, D: DimName> Distribution<Unit<VectorN<N, D>>> for Standard
 where
     DefaultAllocator: Allocator<N, D>,
-    StandardNormal: Distribution<N>,
+    rand_distr::StandardNormal: Distribution<N>,
 {
     /// Generate a uniformly distributed random unit vector.
     #[inline]
@@ -808,7 +810,7 @@ where
         Unit::new_normalize(VectorN::from_distribution_generic(
             D::name(),
             U1,
-            &StandardNormal,
+            &rand_distr::StandardNormal,
             rng,
         ))
     }

src/base/helper.rs

@@ -1,3 +1,4 @@
+#![cfg(feature = "rand")]
 #[cfg(feature = "arbitrary")]
 use quickcheck::{Arbitrary, Gen};
 use rand::distributions::{Distribution, Standard};

src/geometry/isometry_construction.rs

@@ -4,8 +4,8 @@ use crate::base::storage::Owned;
 use quickcheck::{Arbitrary, Gen};
 
 use num::One;
-use rand::distributions::{Distribution, Standard};
+#[cfg(feature = "rand")]
-use rand::Rng;
+use rand::{Rng, distributions::{Distribution, Standard}};
 
 use alga::general::RealField;
 use alga::linear::Rotation as AlgaRotation;
@@ -75,6 +75,7 @@ where DefaultAllocator: Allocator<N, D>
     }
 }
 
+#[cfg(feature = "rand")]
 impl<N: RealField, D: DimName, R> Distribution<Isometry<N, D, R>> for Standard
 where
     R: AlgaRotation<Point<N, D>>,

src/geometry/orthographic.rs

@@ -1,7 +1,7 @@
 #[cfg(feature = "arbitrary")]
 use quickcheck::{Arbitrary, Gen};
-use rand::distributions::{Distribution, Standard};
+#[cfg(feature = "rand")]
-use rand::Rng;
+use rand::{Rng, distributions::{Distribution, Standard}};
 #[cfg(feature = "serde-serialize")]
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
 use std::fmt;
@@ -10,6 +10,7 @@ use std::mem;
 use alga::general::RealField;
 
 use crate::base::dimension::U3;
+#[cfg(feature = "rand")]
 use crate::base::helper;
 use crate::base::storage::Storage;
 use crate::base::{Matrix4, Vector, Vector3};
@@ -678,6 +679,7 @@ impl<N: RealField> Orthographic3<N> {
     }
 }
 
+#[cfg(feature = "rand")]
 impl<N: RealField> Distribution<Orthographic3<N>> for Standard
 where Standard: Distribution<N>
 {

src/geometry/perspective.rs

@@ -1,7 +1,7 @@
 #[cfg(feature = "arbitrary")]
 use quickcheck::{Arbitrary, Gen};
-use rand::distributions::{Distribution, Standard};
+#[cfg(feature = "rand")]
-use rand::Rng;
+use rand::{Rng, distributions::{Distribution, Standard}};
 
 #[cfg(feature = "serde-serialize")]
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
@@ -11,6 +11,7 @@ use std::mem;
 use alga::general::RealField;
 
 use crate::base::dimension::U3;
+#[cfg(feature = "rand")]
 use crate::base::helper;
 use crate::base::storage::Storage;
 use crate::base::{Matrix4, Scalar, Vector, Vector3};
@@ -261,6 +262,7 @@ impl<N: RealField> Perspective3<N> {
     }
 }
 
+#[cfg(feature = "rand")]
 impl<N: RealField> Distribution<Perspective3<N>> for Standard
 where Standard: Distribution<N>
 {

src/geometry/point_construction.rs

@@ -2,8 +2,8 @@
 use quickcheck::{Arbitrary, Gen};
 
 use num::{Bounded, One, Zero};
-use rand::distributions::{Distribution, Standard};
+#[cfg(feature = "rand")]
-use rand::Rng;
+use rand::{Rng, distributions::{Distribution, Standard}};
 
 use alga::general::ClosedDiv;
 use crate::base::allocator::Allocator;
@@ -126,6 +126,7 @@ where DefaultAllocator: Allocator<N, D>
     }
 }
 
+#[cfg(feature = "rand")]
 impl<N: Scalar, D: DimName> Distribution<Point<N, D>> for Standard
 where
     DefaultAllocator: Allocator<N, D>,

src/geometry/quaternion_construction.rs

@@ -6,8 +6,8 @@ use crate::base::storage::Owned;
 use quickcheck::{Arbitrary, Gen};
 
 use num::{One, Zero};
-use rand::distributions::{Distribution, OpenClosed01, Standard};
+#[cfg(feature = "rand")]
-use rand::Rng;
+use rand::{Rng, distributions::{Distribution, OpenClosed01, Standard}};
 
 use alga::general::RealField;
 
@@ -124,6 +124,7 @@ impl<N: RealField> Zero for Quaternion<N> {
     }
 }
 
+#[cfg(feature = "rand")]
 impl<N: RealField> Distribution<Quaternion<N>> for Standard
 where Standard: Distribution<N>
 {
@@ -685,6 +686,7 @@ impl<N: RealField> One for UnitQuaternion<N> {
     }
 }
 
+#[cfg(feature = "rand")]
 impl<N: RealField> Distribution<UnitQuaternion<N>> for Standard
 where OpenClosed01: Distribution<N>
 {
@@ -722,10 +724,10 @@ where
     }
 }
 
-#[cfg(test)]
+#[cfg(all(test, feature="rand"))]
 mod tests {
     use super::*;
-    use rand::{SeedableRng, rngs::SmallRng};
+    use rand::{Rng, SeedableRng, rngs::SmallRng};
 
     #[test]
     fn random_unit_quats_are_unit() {

src/geometry/rotation_specialization.rs

@@ -5,7 +5,9 @@ use quickcheck::{Arbitrary, Gen};
 
 use alga::general::RealField;
 use num::Zero;
+#[cfg(feature = "rand")]
 use rand::distributions::{Distribution, OpenClosed01, Standard, uniform::SampleUniform};
+#[cfg(feature = "rand")]
 use rand::Rng;
 use std::ops::Neg;
 
@@ -230,6 +232,7 @@ impl<N: RealField> Rotation2<N> {
     }
 }
 
+#[cfg(feature = "rand")]
 impl<N: RealField> Distribution<Rotation2<N>> for Standard
 where N: SampleUniform
 {
@@ -817,6 +820,7 @@ impl<N: RealField> Rotation3<N> {
     }
 }
 
+#[cfg(feature = "rand")]
 impl<N: RealField> Distribution<Rotation3<N>> for Standard
 where OpenClosed01: Distribution<N>, N: SampleUniform
 {

src/geometry/similarity_construction.rs

@@ -4,8 +4,8 @@ use crate::base::storage::Owned;
 use quickcheck::{Arbitrary, Gen};
 
 use num::One;
-use rand::distributions::{Distribution, Standard};
+#[cfg(feature = "rand")]
-use rand::Rng;
+use rand::{Rng, distributions::{Distribution, Standard}};
 
 use alga::general::RealField;
 use alga::linear::Rotation as AlgaRotation;
@@ -57,6 +57,7 @@ where
     }
 }
 
+#[cfg(feature = "rand")]
 impl<N: RealField, D: DimName, R> Distribution<Similarity<N, D, R>> for Standard
 where
     R: AlgaRotation<Point<N, D>>,

src/geometry/translation_construction.rs

@@ -4,8 +4,8 @@ use crate::base::storage::Owned;
 use quickcheck::{Arbitrary, Gen};
 
 use num::{One, Zero};
-use rand::distributions::{Distribution, Standard};
+#[cfg(feature = "rand")]
-use rand::Rng;
+use rand::{Rng, distributions::{Distribution, Standard}};
 
 use alga::general::ClosedAdd;
 
@@ -47,6 +47,7 @@ where DefaultAllocator: Allocator<N, D>
     }
 }
 
+#[cfg(feature = "rand")]
 impl<N: Scalar, D: DimName> Distribution<Translation<N, D>> for Standard
 where
     DefaultAllocator: Allocator<N, D>,

src/geometry/unit_complex_construction.rs

@@ -3,7 +3,9 @@ use quickcheck::{Arbitrary, Gen};
 
 use num::One;
 use num_complex::Complex;
+#[cfg(feature = "rand_distr")]
 use rand::distributions::{Distribution, Standard};
+#[cfg(feature = "rand_distr")]
 use rand::Rng;
 
 use alga::general::RealField;
@@ -275,7 +277,7 @@ impl<N: RealField> One for UnitComplex<N> {
     }
 }
 
-#[cfg(feature = "std")]
+#[cfg(feature = "rand_distr")]
 impl<N: RealField> Distribution<UnitComplex<N>> for Standard
 where rand_distr::UnitCircle: Distribution<[N; 2]>
 {
@@ -287,17 +289,6 @@ where rand_distr::UnitCircle: Distribution<[N; 2]>
     }
 }
 
-#[cfg(not(feature = "std"))]
-impl<N: RealField> Distribution<UnitComplex<N>> for Standard
-where N: rand::distributions::uniform::SampleUniform
-{
-    /// Generate a uniformly distributed random `UnitComplex`.
-    #[inline]
-    fn sample<'a, R: Rng + ?Sized>(&self, rng: &mut R) -> UnitComplex<N> {
-        UnitComplex::from_angle(rng.gen_range(N::zero(), N::two_pi()))
-    }
-}
-
 #[cfg(feature = "arbitrary")]
 impl<N: RealField + Arbitrary> Arbitrary for UnitComplex<N> {
     #[inline]

src/lib.rs

@@ -112,7 +112,6 @@ extern crate matrixmultiply;
 extern crate num_complex;
 extern crate num_traits as num;
 extern crate num_rational;
-extern crate rand;
 extern crate typenum;
 
 extern crate alga;

src/linalg/symmetric_eigen.rs

@@ -354,7 +354,7 @@ mod test {
         }
     }
 
-    #[cfg(feature = "std")]
+    #[cfg(feature = "rand_with_std")]
     #[test]
     fn wilkinson_shift_random() {
         for _ in 0..1000 {

tests/core/matrix.rs

@@ -466,6 +466,7 @@ fn zip_map() {
     assert_eq!(computed, expected);
 }
 
+#[cfg(feature = "rand_with_std")]
 #[test]
 #[should_panic]
 fn trace_panic() {