add comment with intention to refactor trig functions in terms of sin_cos_tau

diff --git a/src/algorithms/trig_pi.rs b/src/algorithms/trig_pi.rs
index 5be0ad65b017a389823488c1050a1b22eeb51293..834fd9636b1a972a350ebd2cf52bec32fca7829e 100644 (file)
--- a/src/algorithms/trig_pi.rs
+++ b/src/algorithms/trig_pi.rs
@@ -3,6 +3,9 @@ use crate::{
     traits::{Compare, Context, ConvertFrom, ConvertTo, Float, Make, Select},
 };
 
+// TODO: change `sin`/`cos`/`sin_pi`/`cos_pi` implementations to be
+// in terms of `sin_cos_tau` aka. `(sin(2 * pi * x), cos(2 * pi * x))`
+
 mod consts {
     #![allow(clippy::excessive_precision)]
     #![allow(dead_code)]