Difference between revisions of "cpp/named req/AllocatorAwareContainer"
From cppreference.com
m (tweak) |
m (Shorten template names. Use {{lc}} where appropriate.) |
||
| Line 21: | Line 21: | ||
===Requirements=== | ===Requirements=== | ||
| − | {{ | + | {{dsc begin}} |
| − | {{ | + | {{dsc h1|Legend}} |
| − | {{ | + | {{dsc|{{ttb|X}}|Container type}} |
| − | {{ | + | {{dsc|{{ttb|T}}|Element type}} |
| − | {{ | + | {{dsc|{{ttb|A}}|Allocator for {{ttb|T}} }} |
| − | {{ | + | {{dsc|{{ttb|a}}, {{ttb|b}}|Objects of type {{ttb|X}} (non-const lvalue)}} |
| − | {{ | + | {{dsc|{{ttb|t}}|Object of type {{ttb|T}} (lvalue or const rvalue) }} |
| − | {{ | + | {{dsc|{{ttb|rv}}|Object of type {{ttb|T}} (non-const rvalue) }} |
| − | {{ | + | {{dsc|{{ttb|m}}|Object of type {{ttb|A}} }} |
| − | {{ | + | {{dsc|{{ttb|Q}}| Allocator type }} |
| − | {{ | + | {{dsc end}} |
| Line 71: | Line 71: | ||
===Standard library=== | ===Standard library=== | ||
| − | All standard library containers except {{ | + | All standard library containers except {{lc|std::array}} are {{concept|AllocatorAwareContainer}}s: |
| − | * {{ | + | * {{lc|std::basic_string}} |
| − | * {{ | + | * {{lc|std::deque}} |
| − | * {{ | + | * {{lc|std::forward_list}} |
| − | * {{ | + | * {{lc|std::list}} |
| − | * {{ | + | * {{lc|std::vector}} |
| − | * {{ | + | * {{lc|std::map}} |
| − | * {{ | + | * {{lc|std::multimap}} |
| − | * {{ | + | * {{lc|std::set}} |
| − | * {{ | + | * {{lc|std::multiset}} |
| − | * {{ | + | * {{lc|std::unordered_map}} |
| − | * {{ | + | * {{lc|std::unordered_multimap}} |
| − | * {{ | + | * {{lc|std::unordered_set}} |
| − | * {{ | + | * {{lc|std::unordered_multiset}} |
Revision as of 18:35, 31 May 2013
Template:cpp/concept/title Template:cpp/concept/navbar
An Template:concept is a Template:concept that holds an instance of an Template:concept and uses that instance to allocate and deallocate memory in all of its member functions.
The following rules apply to object construction
- Copy constructors of Template:concepts obtain their instances of the allocator by calling std::allocator_traits<allocator_type>::select_on_container_copy_construction.
- Move constructors obtain their instances of allocators by move-constructing from the allocator belonging to the old container.
- All other constructors take an allocator parameter.
The only way to replace an allocator is copy-assignment, move-assignment, and swap:
- Copy-assignment will replace the allocator only if std::allocator_traits<allocator_type>::propagate_on_container_copy_assignment::value is true
- Move-assignment will replace the allocator only if std::allocator_traits<allocator_type>::propagate_on_container_move_assignment::value is true
- Swap will replace the allocator only if std::allocator_traits<allocator_type>::propagate_on_container_swap::value is true. Specifically, it will exchange the allocator instances through an unqualified call to the non-member function swap, see Template:concept.
Note: swapping two containers with unequal allocators if propagate_on_container_swap is false is undefined behavior.
- The accessor
get_allocator()obtains a copy of the allocator that was used to construct the container or installed by the most recent allocator replacement operation.
Contents |
Requirements
Legend | |
X
|
Container type |
T
|
Element type |
A
|
Allocator for T
|
a, b
|
Objects of type X (non-const lvalue)
|
t
|
Object of type T (lvalue or const rvalue)
|
rv
|
Object of type T (non-const rvalue)
|
m
|
Object of type A
|
Q
|
Allocator type |
| expression | return type | pre/requirements | post/effects | complexity |
|---|---|---|---|---|
| allocator_type | A |
allocator_type::value_type must be the same as X::value_type | constant | |
| get_allocator() | A |
constant | ||
| X u; | u.empty() == true && u.get_allocator() == A() | constant | ||
| X u(m); | u.empty() == true && u.get_allocator() == m | constant | ||
| X u(t,m); | u == t && u.get_allocator() == m | linear | ||
| X u(rv); | Move constructor of A must not throw exceptions
|
u has the same elements and an equal allocator as rv had before the construction |
constant | |
| X u(rv,m); | The elements of u are the same or copies of those of rv and u.get_allocator() == m
|
constant if m == rv.get_allocator(), otherwise linear | ||
| a = t | X& | a == t | linear | |
| a = rv | X& | All existing elements of a are either move assigned to or destroyed |
linear | |
| a.swap(b) | void | Exchanges the contents of a and b |
constant |
Concept requirements
- A
- T
- X
Standard library
All standard library containers except std::array are Template:concepts:
