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Fix outdated limitations in std containers.

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Ion Gaztañaga
2017-09-07 20:16:48 +02:00
parent ac718c54ed
commit b6f688321c
1 changed files with 9 additions and 4 deletions
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doc/intrusive.qbk
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@@ -144,9 +144,11 @@ A non-intrusive container has some limitations:
a size overhead for each allocation to store bookkeeping information and a a size overhead for each allocation to store bookkeeping information and a
synchronization to protected concurrent allocation from different threads. synchronization to protected concurrent allocation from different threads.
* Only copies of objects are stored in non-intrusive containers. Hence copy * Before C++11, only copies of objects could be stored in non-intrusive containers. Still
or move constructors and copy or move assignment operators are required. Non-copyable copy or move constructors and copy or move assignment operators are required
and non-movable objects can't be stored in non-intrusive containers. and non-copyable and non-movable objects can't be stored in some containers. In any case,
[*new] objects have to be created inside the container using constructors and the same
object can't be shared between two containers.
* It's not possible to store a derived object in a STL-container while * It's not possible to store a derived object in a STL-container while
retaining its original type. retaining its original type.
@@ -156,6 +158,9 @@ Intrusive containers have some important advantages:
* Operating with intrusive containers doesn't invoke any memory management at all. * Operating with intrusive containers doesn't invoke any memory management at all.
The time and size overhead associated with dynamic memory can be minimized. The time and size overhead associated with dynamic memory can be minimized.
* The same object can be inserted in more than one container at the same time with
a tiny overhead in the object size.
* Iterating an Intrusive container needs less memory accesses than the semantically * Iterating an Intrusive container needs less memory accesses than the semantically
equivalent container of pointers: iteration is faster. equivalent container of pointers: iteration is faster.
@@ -208,7 +213,7 @@ Intrusive containers have also downsides:
[[Memory management] [External] [Internal through allocator]] [[Memory management] [External] [Internal through allocator]]
[[Insertion/Erasure time] [Faster] [Slower]] [[Insertion/Erasure time] [Faster] [Slower]]
[[Memory locality] [Better] [Worse]] [[Memory locality] [Better] [Worse]]
[[Can hold non-copyable and non-movable objects by value] [Yes] [No]] [[Can insert the same object in more than one container] [Yes] [No]]
[[Exception guarantees] [Better] [Worse]] [[Exception guarantees] [Better] [Worse]]
[[Computation of iterator from value] [Constant] [Non-constant]] [[Computation of iterator from value] [Constant] [Non-constant]]
[[Insertion/erasure predictability] [High] [Low]] [[Insertion/erasure predictability] [High] [Low]]