Unique Hashed Associative Container


Category: containers	Component type: concept

Description

A Unique Hashed Associative Container is a Hashed Associative Container that is also a Unique Associative Container. That is, it is a Hashed Associative Container with the property that no two elements in the container have the same key.

Refinement of

Hashed Associative Container, Unique Associative Container

Associated types

None, except for those described in the Hashed Associative Container and Unique Associative Container requirements.

Notation

`X`	A type that is a model of Hashed Associative Container
`a`	Object of type `X`
`t`	Object of type `X::value_type`
`k`	Object of type `X::key_type`
`p`, `q`	Object of type `X::iterator`
`n`	Object of type `X::size_type`
`h`	Object of type `X::hasher`
`c`	Object of type `X::key_equal`

Definitions

Valid expressions

In addition to the expressions defined in Hashed Associative Container and Unique Associative Container, the following expressions must be valid.

Name	Expression	Type requirements	Return type
Range constructor	X(i, j) X a(i, j);	`i` and `j` are Input Iterators whose value type is convertible to `T` [1].	`X`
Range constructor with bucket count	X(i, j, n) X a(i, j, n);	`i` and `j` are Input Iterators whose value type is convertible to `T` [1].	`X`
Range constructor with hash function	X(i, j, n, h) X a(i, j, n, h);	`i` and `j` are Input Iterators whose value type is convertible to `T` [1].	`X`
Range constructor with key equal	X(i, j, n, h, k) X a(i, j, n, h, k);	`i` and `j` are Input Iterators whose value type is convertible to `T` [1].	`X`

Expression semantics

Name	Expression	Precondition	Semantics	Postcondition
Range constructor	X(i, j) X a(i, j);	`[i,j)` is a valid range.	Creates an associative container that contains all of the elements in the range `[i,j)` that have unique keys, using `hasher()` as the hash function and `key_equal()` as the key equality function.	`size()` is less than or equal to the distance from `i` to `j`. The bucket count is an unspecified default value. The hash function is `hasher()`, and the key equality function is `key_equal()`.
Range constructor with bucket count	X(i, j, n) X a(i, j, n);	`[i,j)` is a valid range.	Creates an associative container that contains all of the elements in the range `[i,j)` that have unique keys, using at least `n` buckets, and using `hasher()` as the hash function and `key_equal()` as the key equality function.	`size()` is less than or equal to the distance from `i` to `j`. The bucket count is greater than or equal to `n`. The hash function is `hasher()`, and the key equality function is `key_equal()`.
Range constructor with hash function	X(i, j, n, h) X a(i, j, n, h);	`[i,j)` is a valid range.	Creates an associative container that contains all of the elements in the range `[i,j)` that have unique keys, using at least `n` buckets, and using `h` as the hash function and `key_equal()` as the key equality function.	`size()` is less than or equal to the distance from `i` to `j`. The bucket count is greater than or equal to `n`. The hash function is `h`, and the key equality function is `key_equal()`.
Range constructor with key equal	X(i, j, n, h, k) X a(i, j, n, h, k);	`[i,j)` is a valid range.	Creates an associative container that contains all of the elements in the range `[i,j)` that have unique keys, using at least `n` buckets, and using `h` as the hash function and `k` as the key equality function.	`size()` is less than or equal to the distance from `i` to `j`. The bucket count is greater than or equal to `n`. The hash function is `h`, and the key equality function is `k`.

Complexity guarantees

The range constructor, range constructor with bucket count, range constructor with hash function, and range constructor with key equal, are all linear in j - i.

Invariants

Models

hash_set
hash_map

Notes

[1] At present (early 1998), not all compilers support "member templates". If your compiler supports member templates then i and j may be of any type that conforms to the Input Iterator requirements. If your compiler does not yet support member templates, however, then i and j must be of type const T* or of type X::const_iterator.