♻️ Remove blit_swap (#457)

* 🔥 remove egfrd/util/swap.hpp

It is basically the same as core/swap.hpp.

* 🔥 remove blit_swap and use std::swap

In pre-C++11, there is no rvalue reference or std::move. In that era, we
need to avoid deep copy while swapping containers like std::vector.
In C++11, there are many specializations of std::move and move-
constructors and move-assignment-operators.

Author: ToruNiina

ecell4/core/DynamicPriorityQueue.hpp

@@ -23,9 +23,6 @@
 #include <iostream>
 #endif
 
-#include "swap.hpp"
-
-
 namespace ecell4
 {
 
@@ -453,7 +450,8 @@ inline void DynamicPriorityQueue<Titem_, Tcomparator_, Tpolicy_>::pop_by_index(i
     policy_type::pop(index, item.first, items_.back().first);
 
     // 2. pop the item from the items_.
-    blit_swap(item, items_.back());
+    using std::swap; // ADL-based specialization
+    swap(item, items_.back());
     items_.pop_back();
 
     const index_type removed_pos(position_vector_[index]);