[util] Use chunk_size alias instead of N in deque

Using an alias to increase readability. No functional changes.

src/libraries/util/util/deque.h

@@ -13,7 +13,9 @@ template <typename T, unsigned N = 16>
 class deque
 {
 public:
-    struct node { T items[N]; };
+    static constexpr unsigned chunk_size = N;
+
+    struct node { T items[chunk_size]; };
     using list_type = linked_list<node>;
     using node_type = typename list_type::item_type;
 
@@ -21,7 +23,7 @@ public:
     {
     public:
         iterator(node_type *n, size_t i) : node(n), index(i) {
-            if (node && index >= N) { node = node->next(); index = 0; }
+            if (node && index >= chunk_size) { node = node->next(); index = 0; }
         }
         iterator(const iterator &o) : node(o.node), index(o.index) {}
         inline T& operator*() { assert(node); return node->items[index]; }
@@ -33,12 +35,12 @@ public:
             return index == o.index && node == o.node;
         }
     private:
-        void incr() { if (++index >= N) { index = 0; node = node->next(); }}
+        void incr() { if (++index >= chunk_size) { index = 0; node = node->next(); }}
         node_type *node;
         size_t index;
     };
 
-    deque() : m_first {0}, m_next {N} {}
+    deque() : m_first {0}, m_next {chunk_size} {}
 
     deque(deque &&other) :
         m_first {other.m_first},
@@ -60,13 +62,13 @@ public:
             node_type *n = new node_type;
             memset(n, 0, sizeof(node_type));
             m_list.push_front(n);
-            m_first = N;
+            m_first = chunk_size;
         }
         m_list.front()->items[--m_first] = item;
     }
 
     inline void push_back(const T& item) {
-        if (m_next == N) { // need a new block at the end
+        if (m_next == chunk_size) { // need a new block at the end
             node_type *n = new node_type;
             memset(n, 0, sizeof(node_type));
             m_list.push_back(n);
@@ -78,11 +80,11 @@ public:
     inline T pop_front() {
         assert(!empty() && "Calling pop_front() on an empty deque");
         T value = m_list.front()->items[m_first++];
-        if (m_first == N) {
+        if (m_first == chunk_size) {
             delete m_list.pop_front();
             m_first = 0;
             if (m_list.empty())
-                m_next = N;
+                m_next = chunk_size;
         }
         return value;
     }
@@ -92,7 +94,7 @@ public:
         T value = m_list.back()->items[--m_next];
         if (m_next == 0) {
             delete m_list.pop_back();
-            m_next = N;
+            m_next = chunk_size;
             if (m_list.empty())
                 m_first = 0;
         }
@@ -128,7 +130,7 @@ public:
         while (!m_list.empty())
             delete m_list.pop_front();
         m_first = 0;
-        m_next = N;
+        m_next = chunk_size;
     }
 
     iterator begin() { return iterator {m_list.front(), m_first}; }