Add comments noting rust bugs

src/array.rs

@@ -19,6 +19,7 @@ use std::ops::*;
 
 /// An array containing elements of type `Element`
 pub trait Array1 where
+    // FIXME: Ugly type signatures - blocked by rust-lang/rust#24092
     Self: Index<usize, Output = <Self as Array1>::Element>,
     Self: IndexMut<usize, Output = <Self as Array1>::Element>,
 {
@@ -50,6 +51,7 @@ pub trait Array1 where
 
 /// A column-major array
 pub trait Array2 where
+    // FIXME: Ugly type signatures - blocked by rust-lang/rust#24092
     Self: Index<usize, Output = <Self as Array2>::Column>,
     Self: IndexMut<usize, Output = <Self as Array2>::Column>,
 {

src/matrix.rs

@@ -250,6 +250,7 @@ impl<S: Copy + Neg<Output = S>> Matrix4<S> {
 }
 
 pub trait Matrix where
+    // FIXME: Ugly type signatures - blocked by rust-lang/rust#24092
     Self: Array2<
         Element = <<Self as Matrix>::ColumnRow as Vector>::Scalar,
         Column = <Self as Matrix>::ColumnRow,
@@ -268,6 +269,7 @@ pub trait Matrix where
     // for<'a> &'a Self: Div<S, Output = Self>,
     // for<'a> &'a Self: Rem<S, Output = Self>,
 {
+    // FIXME: Will not be needed once equality constraints in where clauses is implemented
     type ColumnRow: Vector;
 
     /// Create a new diagonal matrix using the supplied value.

src/point.rs

@@ -66,7 +66,9 @@ impl<S: BaseNum> Point3<S> {
 }
 
 /// Specifies the numeric operations for point types.
-pub trait Point: Array1<Element = <<Self as Point>::Vector as Vector>::Scalar> + Clone // where
+pub trait Point: Clone where
+    // FIXME: Ugly type signatures - blocked by rust-lang/rust#24092
+    Self: Array1<Element = <<Self as Point>::Vector as Vector>::Scalar>,
     // FIXME: blocked by rust-lang/rust#20671
     //
     // for<'a, 'b> &'a Self: Add<&'b V, Output = Self>,

src/rotation.rs

@@ -25,7 +25,9 @@ use vector::{Vector, Vector2, Vector3};
 
 /// A trait for a generic rotation. A rotation is a transformation that
 /// creates a circular motion, and preserves at least one point in the space.
-pub trait Rotation<P: Point>: PartialEq + ApproxEq<Epsilon = <<P as Point>::Vector as Vector>::Scalar> + Sized where
+pub trait Rotation<P: Point>: PartialEq + Sized where
+    // FIXME: Ugly type signatures - blocked by rust-lang/rust#24092
+    Self: ApproxEq<Epsilon = <<P as Point>::Vector as Vector>::Scalar>,
     <<P as Point>::Vector as Vector>::Scalar: BaseFloat,
 {
     /// Create the identity transform (causes no transformation).

src/transform.rs

@@ -79,6 +79,7 @@ pub struct Decomposed<V: Vector, R> {
 }
 
 impl<P: Point, R: Rotation<P>> Transform<P> for Decomposed<P::Vector, R> where
+    // FIXME: Ugly type signatures - blocked by rust-lang/rust#24092
     <<P as Point>::Vector as Vector>::Scalar: BaseFloat,
 {
     #[inline]
@@ -224,6 +225,7 @@ pub trait ToComponents2<S: BaseFloat, R: Rotation2<S>>: ToComponents<Point2<S>,
 pub trait ToComponents3<S: BaseFloat, R: Rotation3<S>>: ToComponents<Point3<S>, R> {}
 
 pub trait CompositeTransform<P: Point, R: Rotation<P>>: Transform<P> + ToComponents<P, R> where
+    // FIXME: Ugly type signatures - blocked by rust-lang/rust#24092
     <<P as Point>::Vector as Vector>::Scalar: BaseFloat,
 {}
 
@@ -231,6 +233,7 @@ pub trait CompositeTransform2<S: BaseFloat, R: Rotation2<S>>: Transform2<S> + To
 pub trait CompositeTransform3<S: BaseFloat, R: Rotation3<S>>: Transform3<S> + ToComponents3<S, R> {}
 
 impl<P: Point, R: Rotation<P> + Clone> ToComponents<P, R> for Decomposed<P::Vector, R> where
+    // FIXME: Ugly type signatures - blocked by rust-lang/rust#24092
     <<P as Point>::Vector as Vector>::Scalar: BaseFloat,
 {
     fn decompose(&self) -> (P::Vector, R, P::Vector) {

src/vector.rs

@@ -111,7 +111,9 @@ use num::{BaseNum, BaseFloat};
 /// A trait that specifies a range of numeric operations for vectors. Not all
 /// of these make sense from a linear algebra point of view, but are included
 /// for pragmatic reasons.
-pub trait Vector: Array1<Element = <Self as Vector>::Scalar> + Clone // where
+pub trait Vector: Clone where
+    // FIXME: Ugly type signatures - blocked by rust-lang/rust#24092
+    Self: Array1<Element = <Self as Vector>::Scalar>,
     // FIXME: blocked by rust-lang/rust#20671
     //
     // for<'a, 'b> &'a Self: Add<&'b Self, Output = Self>,
@@ -627,6 +629,7 @@ impl<S: BaseNum> Vector4<S> {
 /// Specifies geometric operations for vectors. This is only implemented for
 /// 2-dimensional and 3-dimensional vectors.
 pub trait EuclideanVector: Vector + Sized where
+    // FIXME: Ugly type signatures - blocked by rust-lang/rust#24092
     <Self as Vector>::Scalar: BaseFloat,
     Self: ApproxEq<Epsilon = <Self as Vector>::Scalar>,
 {
@@ -647,6 +650,7 @@ pub trait EuclideanVector: Vector + Sized where
     /// The norm of the vector.
     #[inline]
     fn length(&self) -> Self::Scalar {
+        // Not sure why these annotations are needed
         <<Self as Vector>::Scalar as ::rust_num::Float>::sqrt(self.dot(self))
     }
 
@@ -679,6 +683,7 @@ pub trait EuclideanVector: Vector + Sized where
     /// Normalises the vector to a length of `1`.
     #[inline]
     fn normalize_self(&mut self) {
+        // Not sure why these annotations are needed
         let rlen = <<Self as Vector>::Scalar as ::rust_num::Float>::recip(self.length());
         self.mul_self_s(rlen);
     }