openmesh/src/OpenMesh/Core/Mesh/SmartRange.hh

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#pragma once

#include <utility>

//== NAMESPACES ===============================================================

namespace OpenMesh {

//== FORWARD DECLARATION ======================================================

//== CLASS DEFINITION =========================================================

/// Base class for all smart range types
template <typename RangeT, typename HandleT>
struct SmartRangeT
{
  // TODO: Someone with better c++ knowledge may improve the code below.

  template <typename Functor>
  auto sum(Functor&& f) -> decltype (f(std::declval<HandleT>())+f(std::declval<HandleT>()))
  {
    auto range = static_cast<const RangeT*>(this);
    auto begin = range->begin();
    auto end   = range->end();
    assert(begin != end);
    decltype (f(*begin) + f(*begin)) sum = f(*begin);
    auto it = begin;
    ++it;
    for (; it != end; ++it)
      sum += f(*it);
    return sum;
  }

  template <typename Functor>
  auto avg(Functor&& f) -> decltype (1.0 * (f(std::declval<HandleT>())+f(std::declval<HandleT>())))
  {
    auto range = static_cast<const RangeT*>(this);
    auto begin = range->begin();
    auto end   = range->end();
    assert(begin != end);
    decltype (f(*begin) + f(*begin)) sum = f(*begin);
    auto it = begin;
    ++it;
    int n_elements = 1;
    for (; it != end; ++it)
    {
      sum += f(*it);
      ++n_elements;
    }
    return (1.0 / n_elements) * sum;
  }



};



//=============================================================================
} // namespace OpenMesh
//=============================================================================

//=============================================================================