Explain current issues with trait bounds

README.md

@@ -2,6 +2,16 @@
 
 Lmath is generic linear algebra library for Rust. There is still much to do, unit tests to write, bugs to fix, and performance enhancements to make. Help is much appreciated, so please don't hesitate to send me a pull request.
 
+## Current issues
+
+Some of the trait bounds are currently very brittle and verbose. For example you may see implementations like the following:
+
+    pub impl<T:Copy Num NumCast Trig Exp Extent Ord FuzzyEq> Quat<T>: Quaternion<T> { ... }
+
+Ick! Luckily this will be largely eliminated with trait inheritance which will be coming to Rust in the future. That will mean that the above Quaternion implementation would become something like:
+
+    pub impl<T:FloatExt> Quat<T>: Quaternion<T> { ... }
+
 ## Todo:
 
 - ~~Matrix inversion~~