UMFPACK Numeric/Symbolic Smart Pointer in C++

umfpack.cpp

#include "umfpack.h"

/**
 * Smart pointer versions of the typical "void *Numeric" and
 * "void *Symbolic" defintions.
 *
 * For example:
 *   umfpack_dl_numeric_ptr Numeric;
 *   umfpack_dl_numeric(..., &Numeric, ...);
 *   // No call to umfpack_dl_free_numeric required, as it is
 *   // called automatically when Numeric goes out of scope.
 */
template <void (*umfpack_free)(void**)>
class umfpack_void_ptr {
  void *ptr;

 public:
  umfpack_void_ptr() : ptr(NULL) {}

  // Disable copying.
  umfpack_void_ptr(const umfpack_void_ptr &) = delete;
  umfpack_void_ptr& operator=(const umfpack_void_ptr &) = delete;

  // Allow moving.
  umfpack_void_ptr(umfpack_void_ptr &&other) : ptr(NULL) {
    std::swap(ptr, other.ptr);
  }
  umfpack_void_ptr& operator=(umfpack_void_ptr &&other) {
    std::swap(ptr, other.ptr);
    return *this;
  }

  ~umfpack_void_ptr() {
    if (ptr != NULL)
        umfpack_free(&ptr);
  }

  void ** operator&() { return &ptr; }
  operator void*() { return ptr; }
};

typedef umfpack_void_ptr<umfpack_di_free_numeric> umfpack_di_numeric_ptr;
typedef umfpack_void_ptr<umfpack_di_free_symbolic> umfpack_di_symbolic_ptr;

typedef umfpack_void_ptr<umfpack_dl_free_numeric> umfpack_dl_numeric_ptr;
typedef umfpack_void_ptr<umfpack_dl_free_symbolic> umfpack_dl_symbolic_ptr;

typedef umfpack_void_ptr<umfpack_zi_free_numeric> umfpack_zi_numeric_ptr;
typedef umfpack_void_ptr<umfpack_zi_free_symbolic> umfpack_zi_symbolic_ptr;

typedef umfpack_void_ptr<umfpack_zl_free_numeric> umfpack_zl_numeric_ptr;
typedef umfpack_void_ptr<umfpack_zl_free_symbolic> umfpack_zl_symbolic_ptr;