fix

Author: HDembinski

include/boost/histogram/accumulators/mean.hpp

@@ -30,7 +30,7 @@ class mean {
   using value_type = ValueType;
   using const_reference = const value_type&;
 
-  struct internal_data_type {
+  struct impl_type {
     value_type sum_;
     value_type mean_;
     value_type sum_of_deltas_squared_;
@@ -152,9 +152,9 @@ class mean {
   }
 
 private:
-  friend struct unsafe_access;
+  impl_type data_{0, 0, 0};
 
-  internal_data_type data_{0, 0, 0};
+  friend struct unsafe_access;
 };
 
 } // namespace accumulators

include/boost/histogram/unsafe_access.hpp

@@ -116,8 +116,8 @@ struct unsafe_access {
     @param obj instance of accumulator.
   */
   template <class T>
-  static constexpr auto& accumulators_mean_impl(T&& m) {
-    return m.data_;
+  static constexpr auto& accumulators_mean_impl(T& m) {
+    return reinterpret_cast<typename T::impl_type&>(m);
   }
 };
 

test/accumulators_mean_test.cpp

@@ -118,7 +118,7 @@ int main() {
     a(2);
 
     BOOST_TEST_EQ(a.count(), 2);
-    unsafe_access::accumulators_mean(a).sum_ = 1;
+    unsafe_access::accumulators_mean_impl(a).sum_ = 1;
     BOOST_TEST_EQ(a.count(), 1);
   }