//-----------------------------------------------------------------
//!
//! \brief const-iterator to last element
//!
//! Returns a const-iterator to the last element in the array.
//!
//! \return iterator to last element
//!
const_iterator end() const { return _data.end(); }
//-----------------------------------------------------------------
//!
//! \brief iterator to last element
//!
//! Returns a non-const iterator to the last element in the array.
//!
//! \return iterator to last element
//!
iterator end() { return _data.end(); }