From 1103996b836de3c48c8059b62bdcccb3ad9b3990 Mon Sep 17 00:00:00 2001
From: Eduard Bopp <eduard.bopp@aepsil0n.de>
Date: Sat, 10 Jan 2015 01:36:13 +0100
Subject: [PATCH] Implement Arbitrary for (almost) all types

Rot4 and Iso4 had to be left out, since Rot4 apparently lacks a working
constructor.

Thereby (almost) all types in nalgebra can now be used for quickcheck-style
testing.

"arbitrary" is now a conditionally compiled feature that contains these impls
adding a dependency on quickcheck.
---
 Cargo.toml                 |  7 +++++
 src/lib.rs                 |  3 ++
 src/structs/dmat.rs        | 12 +++++++
 src/structs/dvec.rs        |  9 ++++++
 src/structs/dvec_macros.rs |  8 +++++
 src/structs/iso.rs         |  7 +++++
 src/structs/iso_macros.rs  | 14 +++++++++
 src/structs/mat.rs         | 30 ++++++++++++++++++
 src/structs/ortho.rs       | 32 +++++++++++++++++++
 src/structs/persp.rs       | 22 +++++++++++++
 src/structs/pnt.rs         |  8 +++++
 src/structs/pnt_macros.rs  | 14 +++++++++
 src/structs/quat.rs        | 14 +++++++++
 src/structs/rot.rs         | 22 +++++++++++--
 src/structs/vec.rs         |  9 ++++++
 src/structs/vec_macros.rs  | 12 +++++++
 tests/arbitrary.rs         | 64 ++++++++++++++++++++++++++++++++++++++
 17 files changed, 285 insertions(+), 2 deletions(-)
 create mode 100644 tests/arbitrary.rs

diff --git a/Cargo.toml b/Cargo.toml
index ebf35496..5ca8385d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,5 +15,12 @@ license = "BSD-3-Clause"
 name = "nalgebra"
 path = "src/lib.rs"
 
+[features]
+# Generate arbitrary instances of nalgebra types for testing with quickcheck
+arbitrary = ["quickcheck"]
+
 [dependencies]
 rustc-serialize = "*"
+
+[dependencies.quickcheck]
+optional = true
diff --git a/src/lib.rs b/src/lib.rs
index fb1af57b..3177a4e4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -89,6 +89,9 @@ Feel free to add your project to this list if you happen to use **nalgebra**!
 
 extern crate "rustc-serialize" as rustc_serialize;
 
+#[cfg(feature="arbitrary")]
+extern crate quickcheck;
+
 #[cfg(test)]
 extern crate test;
 
diff --git a/src/structs/dmat.rs b/src/structs/dmat.rs
index 44d7dd2d..a6241ac7 100644
--- a/src/structs/dmat.rs
+++ b/src/structs/dmat.rs
@@ -13,6 +13,8 @@ use structs::dvec::DVec;
 use traits::operations::{Inv, Transpose, Mean, Cov};
 use traits::structure::{Cast, ColSlice, RowSlice, Diag, Eye, Indexable, Shape, Zero, One, BaseNum};
 use std::fmt::{Show, Formatter, Result, String};
+#[cfg(feature="arbitrary")]
+use quickcheck::{Arbitrary, Gen};
 
 
 /// Matrix with dimensions unknown at compile-time.
@@ -703,3 +705,13 @@ impl<N: Copy + Sub<N, Output = N>> Sub<N> for DMat<N> {
         res
     }
 }
+
+#[cfg(feature="arbitrary")]
+impl<N: Arbitrary> Arbitrary for DMat<N> {
+    fn arbitrary<G: Gen>(g: &mut G) -> DMat<N> {
+        DMat::from_fn(
+            Arbitrary::arbitrary(g), Arbitrary::arbitrary(g),
+            |_, _| Arbitrary::arbitrary(g)
+        )
+    }
+}
diff --git a/src/structs/dvec.rs b/src/structs/dvec.rs
index 36b78317..e2deb970 100644
--- a/src/structs/dvec.rs
+++ b/src/structs/dvec.rs
@@ -11,6 +11,8 @@ use std::ops::{Add, Sub, Mul, Div, Neg, Index, IndexMut};
 use traits::operations::{ApproxEq, Axpy};
 use traits::geometry::{Dot, Norm};
 use traits::structure::{Iterable, IterableMut, Indexable, Shape, BaseFloat, BaseNum, Zero, One};
+#[cfg(feature="arbitrary")]
+use quickcheck::{Arbitrary, Gen};
 
 /// Heap allocated, dynamically sized vector.
 #[derive(Eq, PartialEq, Show, Clone)]
@@ -78,6 +80,13 @@ impl<N> FromIterator<N> for DVec<N> {
     }
 }
 
+#[cfg(feature="arbitrary")]
+impl<N: Arbitrary> Arbitrary for DVec<N> {
+    fn arbitrary<G: Gen>(g: &mut G) -> DVec<N> {
+        DVec { at: Arbitrary::arbitrary(g) }
+    }
+}
+
 
 dvec_impl!(DVec);
 
diff --git a/src/structs/dvec_macros.rs b/src/structs/dvec_macros.rs
index c64a8c4c..b43c66e1 100644
--- a/src/structs/dvec_macros.rs
+++ b/src/structs/dvec_macros.rs
@@ -520,5 +520,13 @@ macro_rules! small_dvec_from_impl (
                 }
             }
         }
+
+        #[cfg(feature="arbitrary")]
+        impl<N: Arbitrary + Zero> Arbitrary for $dvec<N> {
+            #[inline]
+            fn arbitrary<G: Gen>(g: &mut G) -> $dvec<N> {
+                $dvec::from_fn(g.gen_range(0, $dim), |_| Arbitrary::arbitrary(g))
+            }
+        }
     )
 );
diff --git a/src/structs/iso.rs b/src/structs/iso.rs
index 1005cb96..0dbf768f 100644
--- a/src/structs/iso.rs
+++ b/src/structs/iso.rs
@@ -15,6 +15,9 @@ use structs::vec::{Vec1, Vec2, Vec3, Vec4};
 use structs::pnt::{Pnt2, Pnt3, Pnt4};
 use structs::rot::{Rot2, Rot3, Rot4};
 
+#[cfg(feature="arbitrary")]
+use quickcheck::{Arbitrary, Gen};
+
 
 /// Two dimensional isometry.
 ///
@@ -112,6 +115,7 @@ translate_impl!(Iso2, Pnt2);
 iso_mul_iso_impl!(Iso2);
 iso_mul_pnt_impl!(Iso2, Pnt2);
 pnt_mul_iso_impl!(Iso2, Pnt2);
+arbitrary_iso_impl!(Iso2);
 
 iso_impl!(Iso3, Rot3, Vec3, Vec3);
 rotation_matrix_impl!(Iso3, Rot3, Vec3, Vec3);
@@ -131,6 +135,7 @@ translate_impl!(Iso3, Pnt3);
 iso_mul_iso_impl!(Iso3);
 iso_mul_pnt_impl!(Iso3, Pnt3);
 pnt_mul_iso_impl!(Iso3, Pnt3);
+arbitrary_iso_impl!(Iso3);
 
 // iso_impl!(Iso4, Rot4, Vec4, Vec4);
 // rotation_matrix_impl!(Iso4, Rot4, Vec4, Vec4);
@@ -150,3 +155,5 @@ translate_impl!(Iso4, Pnt4);
 iso_mul_iso_impl!(Iso4);
 iso_mul_pnt_impl!(Iso4, Pnt4);
 pnt_mul_iso_impl!(Iso4, Pnt4);
+// FIXME: as soon as Rot4<N>: Arbitrary
+// arbitrary_iso_impl!(Iso4);
diff --git a/src/structs/iso_macros.rs b/src/structs/iso_macros.rs
index 0bdfd74e..dd0fe303 100644
--- a/src/structs/iso_macros.rs
+++ b/src/structs/iso_macros.rs
@@ -364,3 +364,17 @@ macro_rules! absolute_rotate_impl(
         }
     )
 );
+
+macro_rules! arbitrary_iso_impl(
+    ($t: ident) => (
+        #[cfg(feature="arbitrary")]
+        impl<N: Arbitrary + BaseFloat> Arbitrary for $t<N> {
+            fn arbitrary<G: Gen>(g: &mut G) -> $t<N> {
+                $t::new_with_rotmat(
+                    Arbitrary::arbitrary(g),
+                    Arbitrary::arbitrary(g)
+                )
+            }
+        }
+    )
+);
diff --git a/src/structs/mat.rs b/src/structs/mat.rs
index 64e4460e..5c106c7b 100644
--- a/src/structs/mat.rs
+++ b/src/structs/mat.rs
@@ -15,6 +15,8 @@ use traits::structure::{Cast, Row, Col, Iterable, IterableMut, Dim, Indexable,
 use traits::operations::{Absolute, Transpose, Inv, Outer, EigenQR};
 use traits::geometry::{ToHomogeneous, FromHomogeneous, Orig};
 use linalg;
+#[cfg(feature="arbitrary")]
+use quickcheck::{Arbitrary, Gen};
 
 
 /// Special identity matrix. All its operation are no-ops.
@@ -72,6 +74,7 @@ to_homogeneous_impl!(Mat1, Mat2, 1, 2);
 from_homogeneous_impl!(Mat1, Mat2, 1, 2);
 outer_impl!(Vec1, Mat1);
 eigen_qr_impl!(Mat1, Vec1);
+arbitrary_impl!(Mat1, m11);
 
 /// Square matrix of dimension 2.
 #[derive(Eq, PartialEq, RustcEncodable, RustcDecodable, Clone, Hash, Rand, Show, Copy)]
@@ -120,6 +123,7 @@ to_homogeneous_impl!(Mat2, Mat3, 2, 3);
 from_homogeneous_impl!(Mat2, Mat3, 2, 3);
 outer_impl!(Vec2, Mat2);
 eigen_qr_impl!(Mat2, Vec2);
+arbitrary_impl!(Mat2, m11, m12, m21, m22);
 
 /// Square matrix of dimension 3.
 #[derive(Eq, PartialEq, RustcEncodable, RustcDecodable, Clone, Hash, Rand, Show, Copy)]
@@ -202,6 +206,11 @@ to_homogeneous_impl!(Mat3, Mat4, 3, 4);
 from_homogeneous_impl!(Mat3, Mat4, 3, 4);
 outer_impl!(Vec3, Mat3);
 eigen_qr_impl!(Mat3, Vec3);
+arbitrary_impl!(Mat3,
+    m11, m12, m13,
+    m21, m22, m23,
+    m31, m32, m33
+);
 
 /// Square matrix of dimension 4.
 #[derive(Eq, PartialEq, RustcEncodable, RustcDecodable, Clone, Hash, Rand, Show, Copy)]
@@ -302,6 +311,12 @@ to_homogeneous_impl!(Mat4, Mat5, 4, 5);
 from_homogeneous_impl!(Mat4, Mat5, 4, 5);
 outer_impl!(Vec4, Mat4);
 eigen_qr_impl!(Mat4, Vec4);
+arbitrary_impl!(Mat4,
+  m11, m12, m13, m14,
+  m21, m22, m23, m24,
+  m31, m32, m33, m34,
+  m41, m42, m43, m44
+);
 
 /// Square matrix of dimension 5.
 #[derive(Eq, PartialEq, RustcEncodable, RustcDecodable, Clone, Hash, Rand, Show, Copy)]
@@ -416,6 +431,13 @@ to_homogeneous_impl!(Mat5, Mat6, 5, 6);
 from_homogeneous_impl!(Mat5, Mat6, 5, 6);
 outer_impl!(Vec5, Mat5);
 eigen_qr_impl!(Mat5, Vec5);
+arbitrary_impl!(Mat5,
+  m11, m12, m13, m14, m15,
+  m21, m22, m23, m24, m25,
+  m31, m32, m33, m34, m35,
+  m41, m42, m43, m44, m45,
+  m51, m52, m53, m54, m55
+);
 
 /// Square matrix of dimension 6.
 #[derive(Eq, PartialEq, RustcEncodable, RustcDecodable, Clone, Hash, Rand, Show, Copy)]
@@ -532,3 +554,11 @@ row_slice_impl!(Mat6, Vec6, DVec6, 6);
 diag_impl!(Mat6, Vec6, 6);
 outer_impl!(Vec6, Mat6);
 eigen_qr_impl!(Mat6, Vec6);
+arbitrary_impl!(Mat6,
+  m11, m12, m13, m14, m15, m16,
+  m21, m22, m23, m24, m25, m26,
+  m31, m32, m33, m34, m35, m36,
+  m41, m42, m43, m44, m45, m46,
+  m51, m52, m53, m54, m55, m56,
+  m61, m62, m63, m64, m65, m66
+);
diff --git a/src/structs/ortho.rs b/src/structs/ortho.rs
index fd030bec..238905e5 100644
--- a/src/structs/ortho.rs
+++ b/src/structs/ortho.rs
@@ -2,6 +2,10 @@ use std::num;
 use traits::structure::BaseFloat;
 use structs::{Pnt3, Vec3, Mat4};
 
+#[cfg(feature="arbitrary")]
+use quickcheck::{Arbitrary, Gen};
+
+
 /// A 3D orthographic projection stored without any matrix.
 ///
 /// Reading or modifying its individual properties is cheap but applying the transformation is costly.
@@ -47,6 +51,17 @@ impl<N: BaseFloat> Ortho3<N> {
     }
 }
 
+#[cfg(feature="arbitrary")]
+impl<N: Arbitrary + BaseFloat> Arbitrary for Ortho3<N> {
+    fn arbitrary<G: Gen>(g: &mut G) -> Ortho3<N> {
+        let width = reject(g, |x| !::is_zero(x));
+        let height = reject(g, |x| !::is_zero(x));
+        let znear = Arbitrary::arbitrary(g);
+        let zfar = reject(g, |&x: &N| !::is_zero(&(x - znear)));
+        Ortho3::new(width, height, znear, zfar)
+    }
+}
+
 impl<N: BaseFloat + Clone> Ortho3<N> {
     /// The width of the view cuboid.
     #[inline]
@@ -232,3 +247,20 @@ impl<N: BaseFloat + Clone> OrthoMat3<N> {
         self.mat.clone()
     }
 }
+
+#[cfg(feature="arbitrary")]
+impl<N: Arbitrary + BaseFloat> Arbitrary for OrthoMat3<N> {
+    fn arbitrary<G: Gen>(g: &mut G) -> OrthoMat3<N> {
+        let x: Ortho3<N> = Arbitrary::arbitrary(g);
+        x.to_persp_mat()
+    }
+}
+
+
+/// Simple helper function for rejection sampling
+#[cfg(feature="arbitrary")]
+#[inline]
+pub fn reject<G: Gen, F: FnMut(&T) -> bool, T: Arbitrary>(g: &mut G, f: F) -> T {
+    use std::iter::repeat;
+    repeat(()).map(|_| Arbitrary::arbitrary(g)).filter(f).next().unwrap()
+}
diff --git a/src/structs/persp.rs b/src/structs/persp.rs
index b4b98d70..2e03d69b 100644
--- a/src/structs/persp.rs
+++ b/src/structs/persp.rs
@@ -1,6 +1,10 @@
 use traits::structure::BaseFloat;
 use structs::{Pnt3, Vec3, Mat4};
 
+#[cfg(feature="arbitrary")]
+use quickcheck::{Arbitrary, Gen};
+
+
 /// A 3D perspective projection stored without any matrix.
 ///
 /// Reading or modifying its individual properties is cheap but applying the transformation is costly.
@@ -45,6 +49,16 @@ impl<N: BaseFloat> Persp3<N> {
     }
 }
 
+#[cfg(feature="arbitrary")]
+impl<N: Arbitrary + BaseFloat> Arbitrary for Persp3<N> {
+    fn arbitrary<G: Gen>(g: &mut G) -> Persp3<N> {
+        use structs::ortho::reject;
+        let znear = Arbitrary::arbitrary(g);
+        let zfar = reject(g, |&x: &N| !::is_zero(&(x - znear)));
+        Persp3::new(Arbitrary::arbitrary(g), Arbitrary::arbitrary(g), znear, zfar)
+    }
+}
+
 impl<N: BaseFloat + Clone> Persp3<N> {
     /// Gets the `width / height` aspect ratio.
     #[inline]
@@ -263,3 +277,11 @@ impl<N: BaseFloat + Clone> PerspMat3<N> {
         self.mat.clone()
     }
 }
+
+#[cfg(feature="arbitrary")]
+impl<N: Arbitrary + BaseFloat> Arbitrary for PerspMat3<N> {
+    fn arbitrary<G: Gen>(g: &mut G) -> PerspMat3<N> {
+        let x: Persp3<N> = Arbitrary::arbitrary(g);
+        x.to_persp_mat()
+    }
+}
diff --git a/src/structs/pnt.rs b/src/structs/pnt.rs
index cf9f2aee..8902554c 100644
--- a/src/structs/pnt.rs
+++ b/src/structs/pnt.rs
@@ -12,6 +12,8 @@ use traits::structure::{Cast, Dim, Indexable, Iterable, IterableMut, PntAsVec, S
                         NumPnt, FloatPnt, BaseFloat, BaseNum, Zero, One, Bounded};
 use traits::geometry::{Orig, FromHomogeneous, ToHomogeneous};
 use structs::vec::{Vec1, Vec2, Vec3, Vec4, Vec5, Vec6};
+#[cfg(feature="arbitrary")]
+use quickcheck::{Arbitrary, Gen};
 
 
 /// Point of dimension 0.
@@ -69,6 +71,7 @@ iterable_mut_impl!(Pnt1, 1);
 pnt_to_homogeneous_impl!(Pnt1, Pnt2, y, x);
 pnt_from_homogeneous_impl!(Pnt1, Pnt2, y, x);
 num_float_pnt_impl!(Pnt1, Vec1);
+arbitrary_pnt_impl!(Pnt1, x);
 
 /// Point of dimension 2.
 #[derive(Eq, PartialEq, RustcEncodable, RustcDecodable, Clone, Hash, Rand, Show, Copy)]
@@ -109,6 +112,7 @@ iterable_mut_impl!(Pnt2, 2);
 pnt_to_homogeneous_impl!(Pnt2, Pnt3, z, x, y);
 pnt_from_homogeneous_impl!(Pnt2, Pnt3, z, x, y);
 num_float_pnt_impl!(Pnt2, Vec2);
+arbitrary_pnt_impl!(Pnt2, x, y);
 
 /// Point of dimension 3.
 #[derive(Eq, PartialEq, RustcEncodable, RustcDecodable, Clone, Hash, Rand, Show, Copy)]
@@ -151,6 +155,7 @@ iterable_mut_impl!(Pnt3, 3);
 pnt_to_homogeneous_impl!(Pnt3, Pnt4, w, x, y, z);
 pnt_from_homogeneous_impl!(Pnt3, Pnt4, w, x, y, z);
 num_float_pnt_impl!(Pnt3, Vec3);
+arbitrary_pnt_impl!(Pnt3, x, y, z);
 
 /// Point of dimension 4.
 #[derive(Eq, PartialEq, RustcEncodable, RustcDecodable, Clone, Hash, Rand, Show, Copy)]
@@ -195,6 +200,7 @@ iterable_mut_impl!(Pnt4, 4);
 pnt_to_homogeneous_impl!(Pnt4, Pnt5, a, x, y, z, w);
 pnt_from_homogeneous_impl!(Pnt4, Pnt5, a, x, y, z, w);
 num_float_pnt_impl!(Pnt4, Vec4);
+arbitrary_pnt_impl!(Pnt4, x, y, z, w);
 
 /// Point of dimension 5.
 #[derive(Eq, PartialEq, RustcEncodable, RustcDecodable, Clone, Hash, Rand, Show, Copy)]
@@ -241,6 +247,7 @@ iterable_mut_impl!(Pnt5, 5);
 pnt_to_homogeneous_impl!(Pnt5, Pnt6, b, x, y, z, w, a);
 pnt_from_homogeneous_impl!(Pnt5, Pnt6, b, x, y, z, w, a);
 num_float_pnt_impl!(Pnt5, Vec5);
+arbitrary_pnt_impl!(Pnt5, x, y, z, w, a);
 
 /// Point of dimension 6.
 #[derive(Eq, PartialEq, RustcEncodable, RustcDecodable, Clone, Hash, Rand, Show, Copy)]
@@ -287,3 +294,4 @@ axpy_impl!(Pnt6, x, y, z, w, a, b);
 iterable_impl!(Pnt6, 6);
 iterable_mut_impl!(Pnt6, 6);
 num_float_pnt_impl!(Pnt6, Vec6);
+arbitrary_pnt_impl!(Pnt6, x, y, z, w, a, b);
diff --git a/src/structs/pnt_macros.rs b/src/structs/pnt_macros.rs
index f026a246..acf891f8 100644
--- a/src/structs/pnt_macros.rs
+++ b/src/structs/pnt_macros.rs
@@ -141,3 +141,17 @@ macro_rules! num_float_pnt_impl(
         }
     )
 );
+
+macro_rules! arbitrary_pnt_impl(
+    ($t: ident, $($compN: ident),*) => (
+        #[cfg(feature="arbitrary")]
+        impl<N: Arbitrary> Arbitrary for $t<N> {
+            #[inline]
+            fn arbitrary<G: Gen>(g: &mut G) -> $t<N> {
+                $t {
+                    $($compN: Arbitrary::arbitrary(g),)*
+                }
+            }
+        }
+    )
+);
diff --git a/src/structs/quat.rs b/src/structs/quat.rs
index 17a5090e..5fb4cb4c 100644
--- a/src/structs/quat.rs
+++ b/src/structs/quat.rs
@@ -15,6 +15,10 @@ use traits::structure::{Cast, Indexable, Iterable, IterableMut, Dim, Shape, Base
                         One, Bounded};
 use traits::geometry::{Norm, Rotation, Rotate, Transform};
 
+#[cfg(feature="arbitrary")]
+use quickcheck::{Arbitrary, Gen};
+
+
 /// A quaternion.
 #[derive(Eq, PartialEq, RustcEncodable, RustcDecodable, Clone, Hash, Rand, Show, Copy)]
 pub struct Quat<N> {
@@ -146,6 +150,7 @@ impl<N: ApproxEq<N> + BaseFloat> Div<Quat<N>> for Quat<N> {
     }
 }
 
+
 /// A unit quaternion that can represent a 3D rotation.
 #[derive(Eq, PartialEq, RustcEncodable, RustcDecodable, Clone, Hash, Show, Copy)]
 pub struct UnitQuat<N> {
@@ -470,6 +475,14 @@ impl<N: BaseNum> Transform<Pnt3<N>> for UnitQuat<N> {
     }
 }
 
+#[cfg(feature="arbitrary")]
+impl<N: Arbitrary + BaseFloat> Arbitrary for UnitQuat<N> {
+    fn arbitrary<G: Gen>(g: &mut G) -> UnitQuat<N> {
+        UnitQuat::new(Arbitrary::arbitrary(g))
+    }
+}
+
+
 ord_impl!(Quat, w, i, j, k);
 vec_axis_impl!(Quat, w, i, j, k);
 vec_cast_impl!(Quat, w, i, j, k);
@@ -495,5 +508,6 @@ bounded_impl!(Quat, w, i, j, k);
 axpy_impl!(Quat, w, i, j, k);
 iterable_impl!(Quat, 4);
 iterable_mut_impl!(Quat, 4);
+arbitrary_impl!(Quat, w, i, j, k);
 
 dim_impl!(UnitQuat, 3);
diff --git a/src/structs/rot.rs b/src/structs/rot.rs
index a87ce47c..34c38443 100644
--- a/src/structs/rot.rs
+++ b/src/structs/rot.rs
@@ -11,6 +11,8 @@ use traits::operations::{Absolute, Inv, Transpose, ApproxEq};
 use structs::vec::{Vec1, Vec2, Vec3, Vec4};
 use structs::pnt::{Pnt2, Pnt3, Pnt4};
 use structs::mat::{Mat2, Mat3, Mat4, Mat5};
+#[cfg(feature="arbitrary")]
+use quickcheck::{Arbitrary, Gen};
 
 
 /// Two dimensional rotation matrix.
@@ -19,13 +21,13 @@ pub struct Rot2<N> {
     submat: Mat2<N>
 }
 
-impl<N: Clone + BaseFloat + Neg<Output = N> + Copy> Rot2<N> {
+impl<N: Clone + BaseFloat + Neg<Output = N>> Rot2<N> {
     /// Builds a 2 dimensional rotation matrix from an angle in radian.
     pub fn new(angle: Vec1<N>) -> Rot2<N> {
         let (sia, coa) = angle.x.sin_cos();
 
         Rot2 {
-            submat: Mat2::new(coa.clone(), -sia, sia.clone(), coa)
+            submat: Mat2::new(coa.clone(), -sia, sia, coa)
         }
     }
 }
@@ -87,6 +89,14 @@ impl<N: BaseFloat> AbsoluteRotate<Vec2<N>> for Rot2<N> {
     }
 }
 
+#[cfg(feature="arbitrary")]
+impl<N: Arbitrary + Clone + BaseFloat + Neg<Output = N>> Arbitrary for Rot2<N> {
+    fn arbitrary<G: Gen>(g: &mut G) -> Rot2<N> {
+        Rot2::new(Arbitrary::arbitrary(g))
+    }
+}
+
+
 /*
  * 3d rotation
  */
@@ -287,6 +297,14 @@ impl<N: BaseFloat> AbsoluteRotate<Vec3<N>> for Rot3<N> {
     }
 }
 
+#[cfg(feature="arbitrary")]
+impl<N: Arbitrary + Clone + BaseFloat> Arbitrary for Rot3<N> {
+    fn arbitrary<G: Gen>(g: &mut G) -> Rot3<N> {
+        Rot3::new(Arbitrary::arbitrary(g))
+    }
+}
+
+
 /// Four dimensional rotation matrix.
 #[derive(Eq, PartialEq, RustcEncodable, RustcDecodable, Clone, Show, Hash, Copy)]
 pub struct Rot4<N> {
diff --git a/src/structs/vec.rs b/src/structs/vec.rs
index 92181472..337c1f4d 100644
--- a/src/structs/vec.rs
+++ b/src/structs/vec.rs
@@ -14,6 +14,9 @@ use traits::structure::{Basis, Cast, Dim, Indexable, Iterable, IterableMut, VecA
                         NumVec, FloatVec, BaseFloat, BaseNum, Zero, One, Bounded};
 use structs::pnt::{Pnt1, Pnt2, Pnt3, Pnt4, Pnt5, Pnt6};
 
+#[cfg(feature="arbitrary")]
+use quickcheck::{Arbitrary, Gen};
+
 
 /// Vector of dimension 0.
 #[derive(Eq, PartialEq, RustcDecodable, Clone, Rand, Show, Copy)]
@@ -81,6 +84,7 @@ transform_impl!(Vec1, Pnt1);
 vec_as_pnt_impl!(Vec1, Pnt1, x);
 num_float_vec_impl!(Vec1);
 absolute_vec_impl!(Vec1, x);
+arbitrary_impl!(Vec1, x);
 
 /// Vector of dimension 2.
 #[derive(Eq, PartialEq, RustcEncodable, RustcDecodable, Clone, Hash, Rand, Show, Copy)]
@@ -132,6 +136,7 @@ transform_impl!(Vec2, Pnt2);
 vec_as_pnt_impl!(Vec2, Pnt2, x, y);
 num_float_vec_impl!(Vec2);
 absolute_vec_impl!(Vec2, x, y);
+arbitrary_impl!(Vec2, x, y);
 
 /// Vector of dimension 3.
 #[derive(Eq, PartialEq, RustcEncodable, RustcDecodable, Clone, Hash, Rand, Show, Copy)]
@@ -185,6 +190,7 @@ transform_impl!(Vec3, Pnt3);
 vec_as_pnt_impl!(Vec3, Pnt3, x, y, z);
 num_float_vec_impl!(Vec3);
 absolute_vec_impl!(Vec3, x, y, z);
+arbitrary_impl!(Vec3, x, y, z);
 
 
 /// Vector of dimension 4.
@@ -241,6 +247,7 @@ transform_impl!(Vec4, Pnt4);
 vec_as_pnt_impl!(Vec4, Pnt4, x, y, z, w);
 num_float_vec_impl!(Vec4);
 absolute_vec_impl!(Vec4, x, y, z, w);
+arbitrary_impl!(Vec4, x, y, z, w);
 
 /// Vector of dimension 5.
 #[derive(Eq, PartialEq, RustcEncodable, RustcDecodable, Clone, Hash, Rand, Show, Copy)]
@@ -298,6 +305,7 @@ transform_impl!(Vec5, Pnt5);
 vec_as_pnt_impl!(Vec5, Pnt5, x, y, z, w, a);
 num_float_vec_impl!(Vec5);
 absolute_vec_impl!(Vec5, x, y, z, w, a);
+arbitrary_impl!(Vec5, x, y, z, w, a);
 
 /// Vector of dimension 6.
 #[derive(Eq, PartialEq, RustcEncodable, RustcDecodable, Clone, Hash, Rand, Show, Copy)]
@@ -355,3 +363,4 @@ transform_impl!(Vec6, Pnt6);
 vec_as_pnt_impl!(Vec6, Pnt6, x, y, z, w, a, b);
 num_float_vec_impl!(Vec6);
 absolute_vec_impl!(Vec6, x, y, z, w, a, b);
+arbitrary_impl!(Vec6, x, y, z, w, a, b);
diff --git a/src/structs/vec_macros.rs b/src/structs/vec_macros.rs
index 4f083b5b..a8ce93f7 100644
--- a/src/structs/vec_macros.rs
+++ b/src/structs/vec_macros.rs
@@ -844,3 +844,15 @@ macro_rules! absolute_vec_impl(
     }
   )
 );
+
+macro_rules! arbitrary_impl(
+    ($t: ident, $($compN: ident),*) => (
+        #[cfg(feature="arbitrary")]
+        impl<N: Arbitrary> Arbitrary for $t<N> {
+            #[inline]
+            fn arbitrary<G: Gen>(g: &mut G) -> $t<N> {
+                $t { $($compN: Arbitrary::arbitrary(g),)* }
+            }
+        }
+    )
+);
diff --git a/tests/arbitrary.rs b/tests/arbitrary.rs
new file mode 100644
index 00000000..4369ee78
--- /dev/null
+++ b/tests/arbitrary.rs
@@ -0,0 +1,64 @@
+#![cfg(feature="arbitrary")]
+
+extern crate "nalgebra" as na;
+extern crate quickcheck;
+
+use std::rand;
+use quickcheck::{Arbitrary, StdGen};
+use na::*;
+
+
+macro_rules! trivial_arb_test(
+    ($t: ty, $name: ident) => (
+        #[test]
+        fn $name() {
+            let mut g = StdGen::new(rand::thread_rng(), 100);
+            let _: $t = Arbitrary::arbitrary(&mut g);
+        }
+    )
+);
+
+trivial_arb_test!(Vec1<f64>, arb_vec1);
+trivial_arb_test!(Vec2<f64>, arb_vec2);
+trivial_arb_test!(Vec3<f64>, arb_vec3);
+trivial_arb_test!(Vec4<f64>, arb_vec4);
+trivial_arb_test!(Vec5<f64>, arb_vec5);
+trivial_arb_test!(Vec6<f64>, arb_vec6);
+
+trivial_arb_test!(Pnt1<f64>, arb_pnt1);
+trivial_arb_test!(Pnt2<f64>, arb_pnt2);
+trivial_arb_test!(Pnt3<f64>, arb_pnt3);
+trivial_arb_test!(Pnt4<f64>, arb_pnt4);
+trivial_arb_test!(Pnt5<f64>, arb_pnt5);
+trivial_arb_test!(Pnt6<f64>, arb_pnt6);
+
+trivial_arb_test!(Mat1<f64>, arb_mat1);
+trivial_arb_test!(Mat2<f64>, arb_mat2);
+trivial_arb_test!(Mat3<f64>, arb_mat3);
+trivial_arb_test!(Mat4<f64>, arb_mat4);
+trivial_arb_test!(Mat5<f64>, arb_mat5);
+trivial_arb_test!(Mat6<f64>, arb_mat6);
+
+trivial_arb_test!(DVec1<f64>, arb_dvec1);
+trivial_arb_test!(DVec2<f64>, arb_dvec2);
+trivial_arb_test!(DVec3<f64>, arb_dvec3);
+trivial_arb_test!(DVec4<f64>, arb_dvec4);
+trivial_arb_test!(DVec5<f64>, arb_dvec5);
+trivial_arb_test!(DVec6<f64>, arb_dvec6);
+
+trivial_arb_test!(DMat<f64>, arb_dmat);
+trivial_arb_test!(DVec<f64>, arb_dvec);
+
+trivial_arb_test!(Quat<f64>, arb_quat);
+trivial_arb_test!(UnitQuat<f64>, arb_unit_quat);
+
+trivial_arb_test!(Iso2<f64>, arb_iso2);
+trivial_arb_test!(Iso3<f64>, arb_iso3);
+
+trivial_arb_test!(Rot2<f64>, arb_rot2);
+trivial_arb_test!(Rot3<f64>, arb_rot3);
+
+trivial_arb_test!(Ortho3<f64>, arb_ortho3);
+trivial_arb_test!(OrthoMat3<f64>, arb_ortho_mat3);
+trivial_arb_test!(Persp3<f64>, arb_persp3);
+trivial_arb_test!(PerspMat3<f64>, arb_persp_mat3);