|Parameterized by a function object `Hash` and an equivalence relation `Pred`
|Keys can be compared using `key_compare` which is accessed by member function `key_comp()`, values can be compared using `value_compare` which is accessed by member function `value_comp()`.
|Keys can be hashed using `hasher` which is accessed by member function `hash_function()`, and checked for equality using `key_equal` which is accessed by member function `key_eq()`. There is no function object for compared or hashing values.
|Constructors have optional extra parameters for the comparison object.
|Constructors have optional extra parameters for the initial minimum number of buckets, a hash function and an equality object.
|Keys `k1`, `k2` are considered equivalent if `!Compare(k1, k2) && !Compare(k2, k1)`.
|Keys `k1`, `k2` are considered equivalent if `Pred(k1, k2)`
|Member function `lower_bound(k)` and `upper_bound(k)`
|No equivalent. Since the elements aren't ordered `lower_bound` and `upper_bound` would be meaningless.
|`equal_range(k)` returns an empty range at the position that `k` would be inserted if `k` isn't present in the container.
|`equal_range(k)` returns a range at the end of the container if `k` isn't present in the container. It can't return a positioned range as `k` could be inserted into multiple place. To find out the bucket that `k` would be inserted into use `bucket(k)`. But remember that an insert can cause the container to rehash - meaning that the element can be inserted into a different bucket.
|`iterator`, `const_iterator` are of the bidirectional category.
|`iterator`, `const_iterator` are of at least the forward category.
|Iterators, pointers and references to the container's elements are never invalidated.
|<<buckets_iterator_invalidation,Iterators can be invalidated by calls to insert or rehash>>. Pointers and references to the container's elements are never invalidated.
|Iterators iterate through the container in the order defined by the comparison object.
|Iterators iterate through the container in an arbitrary order, that can change as elements are inserted, although equivalent elements are always adjacent.
|No equivalent
|Local iterators can be used to iterate through individual buckets. (The order of local iterators and iterators aren't required to have any correspondence.)
|Can be compared using the `==`, `!=`, `<`, `\<=`, `>`, `>=` operators.
|Can be compared using the `==` and `!=` operators.
|
|When inserting with a hint, implementations are permitted to ignore the hint.
|`erase` never throws an exception
|The containers' hash or predicate function can throw exceptions from `erase`.
