From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Tyler Veness <calcmogul@gmail.com>
Date: Sun, 16 Jun 2024 12:08:49 -0700
Subject: [PATCH 02/10] Use wpi::SmallVector

---
 include/sleipnir/autodiff/expression.hpp | 4 ++--
 include/sleipnir/autodiff/variable.hpp   | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/sleipnir/autodiff/expression.hpp b/include/sleipnir/autodiff/expression.hpp
index af10b505ae44ca0eb656f66f3f49172d7fc98c6d..7a9dc089a9e2fb323ecc8725f924ebee1b213af0 100644
--- a/include/sleipnir/autodiff/expression.hpp
+++ b/include/sleipnir/autodiff/expression.hpp
@@ -34,7 +34,7 @@ struct Expression;
 template <typename Scalar>
 constexpr void inc_ref_count(Expression<Scalar>* expr);
 template <typename Scalar>
-constexpr void dec_ref_count(Expression<Scalar>* expr);
+void dec_ref_count(Expression<Scalar>* expr);
 
 /// Typedef for intrusive shared pointer to Expression.
 ///
@@ -744,7 +744,7 @@ constexpr void inc_ref_count(Expression<Scalar>* expr) {
 /// @tparam Scalar Scalar type.
 /// @param expr The shared pointer's managed object.
 template <typename Scalar>
-constexpr void dec_ref_count(Expression<Scalar>* expr) {
+void dec_ref_count(Expression<Scalar>* expr) {
   // If a deeply nested tree is being deallocated all at once, calling the
   // Expression destructor when expr's refcount reaches zero can cause a stack
   // overflow. Instead, we iterate over its children to decrement their
diff --git a/include/sleipnir/autodiff/variable.hpp b/include/sleipnir/autodiff/variable.hpp
index 910ebcf5266bdf76711db7849dd6584549094e3b..3c4f67c1f6224226620e2ffcc597336435943ce8 100644
--- a/include/sleipnir/autodiff/variable.hpp
+++ b/include/sleipnir/autodiff/variable.hpp
@@ -53,7 +53,7 @@ class Variable : public SleipnirBase {
   Variable() = default;
 
   /// Constructs an empty Variable.
-  explicit constexpr Variable(std::nullptr_t) : expr{nullptr} {}
+  explicit Variable(std::nullptr_t) : expr{nullptr} {}
 
   /// Constructs a Variable from a scalar type.
   ///
@@ -96,7 +96,7 @@ class Variable : public SleipnirBase {
   /// Constructs a Variable pointing to the specified expression.
   ///
   /// @param expr The autodiff variable.
-  explicit constexpr Variable(detail::ExpressionPtr<Scalar>&& expr)
+  explicit Variable(detail::ExpressionPtr<Scalar>&& expr)
       : expr{std::move(expr)} {}
 
   /// Assignment operator for scalar.