Move ptr_compare.hpp to the detail folder.

include/pointers/const_propogating_ptr.hpp

@@ -8,8 +8,8 @@
 #pragma once
 #include <memory>
 
+#include "detail/compare.hpp"
 #include "pointer_fwd.hpp"
-#include "ptr_compare.hpp"
 
 template <typename P>
 class const_propogating_ptr

include/pointers/const_ptr.hpp

@@ -8,8 +8,8 @@
 #pragma once
 #include <memory>
 
+#include "detail/compare.hpp"
 #include "pointer_fwd.hpp"
-#include "ptr_compare.hpp"
 
 template <typename P>
 class const_ptr : private detail::get_ptr<P>,

include/pointers/maybe_null.hpp

@@ -10,8 +10,8 @@
 
 #include <memory>
 
+#include "detail/compare.hpp"
 #include "pointer_fwd.hpp"
-#include "ptr_compare.hpp"
 
 class unchecked_pointer_exception : public std::logic_error {
   using std::logic_error::logic_error;

include/pointers/not_null.hpp

@@ -10,9 +10,9 @@
 
 #include <memory>
 
+#include "detail/compare.hpp"
 #include "maybe_null.hpp"
 #include "pointer_fwd.hpp"
-#include "ptr_compare.hpp"
 
 template <typename P>
 class not_null<std::weak_ptr<P>>; // A weak_ptr cannot be a not_null

include/pointers/value_ptr.hpp

@@ -9,8 +9,8 @@
 
 #include <memory>
 
+#include "detail/compare.hpp"
 #include "pointer_fwd.hpp"
-#include "ptr_compare.hpp"
 
 namespace detail {
   template <typename T> using clone_func = T * (T::*)() const;