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Relational Operators

These are non-member functions.

Method
Multimap
Compares the values in the multimap
template <class K, size_t M, class T, class C, class A> bool operator==(const spatial_map<K, M, T, C, A> &lhs, const spatial_map<K, M, T, C, A> &rhs);
template <class K, size_t M, class T, class C, class A> bool operator!=(const spatial_map<K, M, T, C, A> &lhs, const spatial_map<K, M, T, C, A> &rhs);

Parameters

  • lhs, rhs - spatial_maps whose contents to compare

Return value

true if the internal contents of the spatial_maps are equal, false otherwise.

Complexity

\[ O(n) \]

Notes

Warning

This operator tells us if the internal trees are equal and not if they contain the same elements. This is because the standard defines that this operation should take \(O(n)\) time. Two trees might contain the same elements in different subtrees if their insertion order was different.

If you need to compare if the elements of lhs and rhs are the same, regardless of their internal representation, you have to iterate lhs and iteratively call find on the second container. This operation takes \(O(m n \log n)\) time.

We do not include operator<, operator>, operator<=, operator>= for spatial containers because std::lexicographical_compare would be semantically meaningless in a multidimensional context where we need to return a value in \(O(n)\) time and, by definition, there is no priority between key dimensions.

Example

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spatial_map<double, 3, unsigned> m2(m);
if (m == m2) {
    std::cout << "The containers have the same elements" << std::endl;
} else {
    if (m.size() != m2.size()) {
        std::cout << "The containers do not have the same elements" << std::endl;
    } else {
        std::cout << "The containers might not have the same elements" << std::endl;
        // You need a for loop after here to make sure
    }
}

spatial_map<double, 3, unsigned> m3(m.begin(), m.end());
if (m == m3) {
    std::cout << "The containers have the same elements" << std::endl;
} else {
    if (m.size() != m3.size()) {
        std::cout << "The containers do not have the same elements" << std::endl;
    } else {
        std::cout << "The containers might not have the same elements" << std::endl;
        // You need a for loop after here to make sure
    }
}

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m2 = pareto.spatial_map(m)
if m == m2:
    print('The containers have the same elements')
else:
    if len(m) != len(m2):
        print('The containers do not have the same elements')
    else:
        print('The containers might not have the same elements')
        # You need a for loop after here to make sure

m3 = pareto.spatial_map()
for [k, v] in m:
    m3[k] = v

if m == m3:
    print('The containers have the same elements')
else:
    if len(m) != len(m3):
        print('The containers do not have the same elements')
    else:
        print('The containers might not have the same elements')
        # You need a for loop after here to make sure

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The containers have the same elements
The containers might not have the same elements