Repo created

libs/base/array_adapters.hpp

@@ -0,0 +1,71 @@
+#pragma once
+
+#include "base/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); }
+};
+}  // namespace detail
+
+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;
+
+  typedef detail::array_impl<T, T *> base_t;
+
+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(base_t::m_size, m_capacity, ());
+    base_t::m_p[base_t::m_size++] = t;
+  }
+};