
ALINK="#ff0000">
Unique Sorted Associative Container


Category: containers 
Component type: concept 
Description
A Unique Sorted Associative Container is a Sorted Associative
Container that is also a Unique Associative Container. That is,
it is a Sorted Associative Container with the property that no two
elements in the container have the same key.
Refinement of
Sorted Associative Container,
Unique Associative Container
Associated types
None, except for those described in the
Sorted Associative Container
and Unique Associative Container
requirements.
Notation
X

A type that is a model of Unique Sorted 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

c

Object of type X::key_compare

Definitions
Valid expressions
In addition to the expressions defined in
Sorted 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].


Range constructor with compare

X(i, j, c)
X a(i, j, c);

i and j are Input Iterators whose value type is convertible
to T [1]. c is an object of type key_compare.


Insert with hint

a.insert(p, t)


iterator

Insert range

a.insert(i, j)

i and j are Input Iterators whose value type is convertible
to X::value_type. [1]

void

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. The comparison object used by the container
is key_compare().

size() is less than or equal to the distance from i to j.

Range constructor with compare

X(i, j, c)
X a(i, j, c);

[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. The comparison object used by the container
is c.

size() is less than or equal to the distance from i to j.

Insert with hint

a.insert(p, t)

p is a nonsingular iterator in a.

Inserts t into a if and only if a does not already contain
an element whose key is equivalent to t's key. The argument p is a hint:
it points to the location where the search will begin. The return
value is a dereferenceable iterator that points to the element with
a key that is equivalent to that of t.

a contains an element whose key is the same as that of t.
The size of a is incremented by either 1 or 0.

Insert range

a.insert(i, j)

[i, j) is a valid range.

Equivalent to a.insert(t) for each object t that is pointed to
by an iterator in the range [i, j). Each element is inserted into
a if and only if a does not already contain an element with
an equivalent key.

The size of a is incremented by at most j  i.

Complexity guarantees
The range constructor, and range constructor with compare, are in
general O(N * log(N)), where N is the size of the range. However,
they are linear in N if the range is already sorted by
value_comp().
Insert with hint is logarithmic in general, but it is amortized
constant time if t is inserted immediately before p.
Insert range is in general O(N * log(N)), where N is the size of
the range. However, it is linear in N if the range is already
sorted by value_comp().
Invariants
Strictly ascending order

The elements in a Unique Sorted Associative Container are always arranged
in strictly ascending order by key. That is, if a is a Unique Sorted
Associative Container, then is_sorted(a.begin(), a.end(),
a.value_comp()) is always true. Furthermore, if i and j
are dereferenceable iterators in a such that i precedes j,
then a.value_comp()(*i, *j) is always true. [2]

Models
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.
[2]
This is a more stringent invariant than that of
Sorted Associative Container.
In a Sorted Associative Container
we merely know that every element is less
than or equal to its successor; in a
Unique Sorted Associative Container, however,
we know that it must be less than its successor.
See also
Associative Container,
Sorted Associative Container,
Multiple Sorted Associative Container,
Hashed Associative Container
Copyright ©
1999 Silicon Graphics, Inc. All Rights Reserved.
TrademarkInformation
