diff --git a/src/ipa/libipa/pwl.cpp b/src/ipa/libipa/pwl.cpp
index 1ba01085..d8ea92be 100644
--- a/src/ipa/libipa/pwl.cpp
+++ b/src/ipa/libipa/pwl.cpp
@@ -182,6 +182,12 @@ void Pwl::prepend(double x, double y, const double eps)
 		points_.insert(points_.begin(), Point({ x, y }));
 }
 
+/**
+ * \fn Pwl::empty() const
+ * \brief Check if the piecewise linear function is empty
+ * \return True if there are no points in the function, false otherwise
+ */
+
 /**
  * \brief Get the domain of the piecewise linear function
  * \return An interval representing the domain
@@ -203,15 +209,6 @@ Pwl::Interval Pwl::range() const
 	return Interval(lo, hi);
 }
 
-/**
- * \brief Check if the piecewise linear function is empty
- * \return True if there are no points in the function, false otherwise
- */
-bool Pwl::empty() const
-{
-	return points_.empty();
-}
-
 /**
  * \brief Evaluate the piecewise linear function
  * \param[in] x The x value to input into the function
diff --git a/src/ipa/libipa/pwl.h b/src/ipa/libipa/pwl.h
index 4cc257f9..b4de00cf 100644
--- a/src/ipa/libipa/pwl.h
+++ b/src/ipa/libipa/pwl.h
@@ -51,7 +51,7 @@ public:
 
 	void append(double x, double y, double eps = 1e-6);
 
-	bool empty() const;
+	bool empty() const { return points_.empty(); }
 	Interval domain() const;
 	Interval range() const;