Try out operator overloads for Sk2x.

src/core/Sk2x.h

Index: src/core/Sk2x.h
diff --git a/src/core/Sk2x.h b/src/core/Sk2x.h
index 99cd45ebe80403177615e4cd4835305b690a0ae6..5e78c503d5aa5c0cd88e7408dca3252dea68defa 100644
--- a/src/core/Sk2x.h
+++ b/src/core/Sk2x.h
@@ -49,6 +49,14 @@ public:
     Sk2x subtract(const Sk2x&) const;
     Sk2x multiply(const Sk2x&) const;
 
+    Sk2x operator +(const Sk2x& o) const { return this->add(o); }
+    Sk2x operator -(const Sk2x& o) const { return this->subtract(o); }
+    Sk2x operator *(const Sk2x& o) const { return this->multiply(o); }
+
+    Sk2x& operator +=(const Sk2x& o) { return (*this = *this + o); }
+    Sk2x& operator -=(const Sk2x& o) { return (*this = *this - o); }
+    Sk2x& operator *=(const Sk2x& o) { return (*this = *this * o); }
+
     Sk2x rsqrt() const;   // Approximate 1/this->sqrt().
     Sk2x  sqrt() const;   // this->multiply(this->rsqrt()) may be faster, but less precise.