[#prevector-01]
= xref:prevector-0c.adoc[prevector]<36, unsigned char>
:mrdocs:

Implements a drop‐in replacement for std::vector<T> which stores up to N elements directly (without heap allocation). The types Size and Diff are used to store element counts, and can be any unsigned + signed type.

== Synopsis

Declared in `<prevector.h>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<>
class xref:prevector-0c.adoc[prevector]<36, unsigned char>;
----

== Description

Storage layout is either:

* Direct allocation:
* Size _size: the number of used elements (between 0 and N)
* T direct[N]: an array of N elements of type T (only the first _size are initialized).
* Indirect allocation:
* Size _size: the number of used elements plus N + 1
* Size capacity: the number of allocated elements
* T* indirect: a pointer to an array of capacity elements of type T (only the first _size are initialized).

The data type T must be movable by memmove/realloc(). Once we switch to C++, move constructors can be used instead.

== Types

[cols="1,4"]
|===
| Name| Description
| xref:prevector-01/const_iterator.adoc[`const_iterator`] 
| Read‐only contiguous iterator over the container's elements.
| xref:prevector-01/iterator.adoc[`iterator`] 
| Mutable contiguous iterator over the container's elements.
|===


== Type Aliases

[cols="1,4"]
|===
| Name| Description
| xref:prevector-01/const_pointer.adoc[`const_pointer`] 
| Pointer to a const element.
| xref:prevector-01/const_reference.adoc[`const_reference`] 
| Reference to a const element.
| xref:prevector-01/difference_type.adoc[`difference_type`] 
| Signed type used to represent distances between iterators.
| xref:prevector-01/pointer.adoc[`pointer`] 
| Pointer to an element.
| xref:prevector-01/reference.adoc[`reference`] 
| Reference to an element.
| xref:prevector-01/size_type.adoc[`size_type`] 
| Unsigned type used to store element counts.
| xref:prevector-01/value_type.adoc[`value_type`] 
| Type of the elements held by the container.
|===


== Member Functions

[cols="1,4"]
|===
| Name| Description
| xref:prevector-01/2constructor-0d.adoc[`prevector`]         [.small]#[constructor]#
| Constructors
| xref:prevector-01/2destructor.adoc[`~prevector`] [.small]#[destructor]#
| Destroys the container, freeing any heap allocation.
| xref:prevector-01/operator_assign-08.adoc[`operator=`] 
| Assignment operators
| xref:prevector-01/allocated_memory.adoc[`allocated_memory`] 
| Returns the number of bytes held in the heap allocation, or zero when stored inline.
| xref:prevector-01/assign-03.adoc[`assign`] 
| `assign` overloads
| xref:prevector-01/back-0b.adoc[`back`] 
| `back` overloads
| xref:prevector-01/begin-0e.adoc[`begin`] 
| `begin` overloads
| xref:prevector-01/capacity.adoc[`capacity`] 
| Returns the number of elements the container can hold without reallocating.
| xref:prevector-01/clear.adoc[`clear`] 
| Removes all elements, leaving the container empty.
| xref:prevector-01/data-092.adoc[`data`] 
| `data` overloads
| xref:prevector-01/emplace_back.adoc[`emplace_back`] 
| Constructs a new element in place at the end of the container.
| xref:prevector-01/empty.adoc[`empty`] 
| Returns whether the container holds no elements.
| xref:prevector-01/end-01.adoc[`end`] 
| `end` overloads
| xref:prevector-01/erase-0a.adoc[`erase`] 
| `erase` overloads
| xref:prevector-01/front-0d.adoc[`front`] 
| `front` overloads
| xref:prevector-01/insert-07.adoc[`insert`] 
| `insert` overloads
| xref:prevector-01/operator_subs-04.adoc[`operator[]`] 
| Subscript operators
| xref:prevector-01/pop_back.adoc[`pop_back`] 
| Removes the last element.
| xref:prevector-01/push_back.adoc[`push_back`] 
| Appends a copy of `value` to the end of the container.
| xref:prevector-01/reserve.adoc[`reserve`] 
| Ensures capacity for at least `new_capacity` elements without changing the size.
| xref:prevector-01/resize.adoc[`resize`] 
| Resizes the container to hold `new_size` elements, value‐initializing any new ones.
| xref:prevector-01/resize_uninitialized.adoc[`resize_uninitialized`] 
| Changes the size to `new_size` without initializing any newly added elements.
| xref:prevector-01/shrink_to_fit.adoc[`shrink_to_fit`] 
| Reduces the capacity to match the current size.
| xref:prevector-01/size.adoc[`size`] 
| Returns the number of elements currently stored.
| xref:prevector-01/swap.adoc[`swap`] 
| Exchanges the contents of this container with `other`.
| xref:prevector-01/operator_eq.adoc[`operator==`] 
| Returns whether this container holds the same elements as `other`.
| xref:prevector-01/operator_lt.adoc[`operator<`] 
| Orders two containers lexicographically by their elements.
|===


== Static Data Members

[cols="1,4"]
|===
| Name| Description
| xref:prevector-01/STATIC_SIZE.adoc[`STATIC_SIZE`] 
| Number of elements stored inline before switching to heap allocation.
|===



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