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 2/8] Use wpi::SmallVector

---
 include/sleipnir/autodiff/expression.hpp      | 4 ++--
 include/sleipnir/autodiff/variable.hpp        | 5 ++---
 include/sleipnir/autodiff/variable_matrix.hpp | 4 ++--
 3 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/include/sleipnir/autodiff/expression.hpp b/include/sleipnir/autodiff/expression.hpp
index bb4d8c5641a5b3d633d372674e0a35f857889cd4..53a5f6d68d3153537840c4ff45fe5e5d8b0076b7 100644
--- a/include/sleipnir/autodiff/expression.hpp
+++ b/include/sleipnir/autodiff/expression.hpp
@@ -30,7 +30,7 @@ inline constexpr bool USE_POOL_ALLOCATOR = true;
 struct Expression;
 
 inline constexpr void inc_ref_count(Expression* expr);
-inline constexpr void dec_ref_count(Expression* expr);
+inline void dec_ref_count(Expression* expr);
 
 /**
  * Typedef for intrusive shared pointer to Expression.
@@ -733,7 +733,7 @@ inline constexpr void inc_ref_count(Expression* expr) {
  *
  * @param expr The shared pointer's managed object.
  */
-inline constexpr void dec_ref_count(Expression* expr) {
+inline void dec_ref_count(Expression* 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 f60236811eba45c67a9638e90d5101d877ecc2d0..264f0950f293c67d6e6c7e729887090c050e40e2 100644
--- a/include/sleipnir/autodiff/variable.hpp
+++ b/include/sleipnir/autodiff/variable.hpp
@@ -47,7 +47,7 @@ class SLEIPNIR_DLLEXPORT Variable {
   /**
    * Constructs an empty Variable.
    */
-  explicit constexpr Variable(std::nullptr_t) : expr{nullptr} {}
+  explicit Variable(std::nullptr_t) : expr{nullptr} {}
 
   /**
    * Constructs a Variable from a floating point type.
@@ -77,8 +77,7 @@ class SLEIPNIR_DLLEXPORT Variable {
    *
    * @param expr The autodiff variable.
    */
-  explicit constexpr Variable(detail::ExpressionPtr&& expr)
-      : expr{std::move(expr)} {}
+  explicit Variable(detail::ExpressionPtr&& expr) : expr{std::move(expr)} {}
 
   /**
    * Assignment operator for double.
diff --git a/include/sleipnir/autodiff/variable_matrix.hpp b/include/sleipnir/autodiff/variable_matrix.hpp
index e1a419ca5356660b3c1c27230d1cb2a86977fb65..349a1550235516f9853609b61feded834ef2894b 100644
--- a/include/sleipnir/autodiff/variable_matrix.hpp
+++ b/include/sleipnir/autodiff/variable_matrix.hpp
@@ -1120,14 +1120,14 @@ class SLEIPNIR_DLLEXPORT VariableMatrix {
    *
    * @return Begin iterator.
    */
-  const_iterator cbegin() const { return const_iterator{m_storage.cbegin()}; }
+  const_iterator cbegin() const { return const_iterator{m_storage.begin()}; }
 
   /**
    * Returns end iterator.
    *
    * @return End iterator.
    */
-  const_iterator cend() const { return const_iterator{m_storage.cend()}; }
+  const_iterator cend() const { return const_iterator{m_storage.end()}; }
 
   /**
    * Returns number of elements in matrix.