libMesh::ElemHashUtils Struct Reference

A struct providing convenience functions for hashing elements. More...

#include <elem_hash.h>

Public Member Functions
std::size_t	operator() (const Elem *elem) const
bool	operator() (const Elem *lhs, const Elem *rhs) const

Detailed Description

A struct providing convenience functions for hashing elements.

The ElemHashUtils struct defines functions used for the "Hash" and "Pred" template arguments of the various "unordered" containers, e.g. template <class Key, // unordered_multiset::key_type/value_type class Hash = hash<Key>, // unordered_multiset::hasher class Pred = equal_to<Key>, // unordered_multiset::key_equal class Alloc = allocator<Key> // unordered_multiset::allocator_type > class unordered_multiset;

Author

John W. Peterson

Date

2015

Definition at line 46 of file elem_hash.h.

Member Function Documentation

operator()() [1/2]

std::size_t libMesh::ElemHashUtils::operator() ( const Elem *  elem ) const

inline

The "Hash" template argument. A custom hash functor that can be used with the "unordered" container types.

Returns

A hash for the element computed by calling elem->key().

Definition at line 56 of file elem_hash.h.

References libMesh::Elem::key().

  {
    return cast_int<std::size_t>(elem->key());
  }

operator()() [2/2]

bool libMesh::ElemHashUtils::operator() ( const Elem *  lhs, const Elem *  rhs  ) const

inline

Satisfies the requirements of the "Pred" template parameter of the standard hash containers. We need to specify this in order to use the unordered_multiset, otherwise it just uses std::equal_to to compare two pointers...

Returns

true if the two Elem keys are equal, false otherwise.

Definition at line 70 of file elem_hash.h.

References libMesh::Elem::key().

  {
    return lhs->key() == rhs->key();
  }

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The documentation for this struct was generated from the following file:

• elem_hash.h