Add C-style array adapters for reading and writing.

base/array_adapters.h

@@ -0,0 +1,68 @@
+#pragma once
+#include "assert.hpp"
+
+
+namespace detail
+{
+  template <class T, class TPtr> class array_impl
+  {
+  protected:
+    TPtr m_p;
+    size_t m_size;
+
+  public:
+    typedef T value_type;
+    typedef T const & const_reference;
+    typedef T & reference;
+
+    array_impl(TPtr p, size_t sz) : m_p(p), m_size(sz) {}
+
+    T const & operator[](size_t i) const
+    {
+      ASSERT_LESS ( i, m_size, () );
+      return m_p[i]; 
+    }
+
+    T const & back() const
+    {
+      ASSERT_GREATER ( m_size, 0, () );
+      return m_p[m_size-1];
+    }
+
+    size_t size() const { return m_size; }
+
+    bool empty() const { return (m_size == 0); }
+  };
+}
+
+template <class T> class array_read : public detail::array_impl<T, T const *>
+{
+public:
+  array_read(T const * p, size_t sz)
+    : detail::array_impl<T, T const *>(p, sz)
+  {
+  }
+};
+
+template <class TCont>
+array_read<typename TCont::value_type> make_read_adapter(TCont const & cont)
+{
+  return array_read<typename TCont::value_type>(cont.empty() ? 0 : &cont[0], cont.size());
+}
+
+template <class T> class array_write : public detail::array_impl<T, T *>
+{
+  size_t m_capacity;
+
+public:
+  template <class TCont> explicit array_write(TCont & cont)
+    : detail::array_impl<T, T *>(cont.empty() ? 0 : &cont[0], 0), m_capacity(cont.size())
+  {
+  }
+
+  void push_back(T const & t)
+  {
+    ASSERT_LESS ( m_size, m_capacity, () );
+    m_p[m_size++] = t; 
+  }
+};

base/base.pro

@@ -59,4 +59,5 @@ HEADERS += \
     shared_buffer_manager.hpp \
     memory_mapped_file.hpp \
     buffer_vector.hpp \
-    path_utils.hpp
+    path_utils.hpp \
+    array_adapters.hpp \