Home » What variations of vector-like containers already widely established? Do I have to write my own? [closed]

What variations of vector-like containers already widely established? Do I have to write my own? [closed]


Here are the ones I know of:

  • Traditional a.k.a. plain a.k.a. C array
  • vector
  • unique_ptr with an array-type template argument
  • array
  • valarray
  • dynarray
  • static_vector (see also here)
  • small_vector
  • stable_vector

There are also “variable-length arrays” and “arrays with runtime bounds”, which do not exist in C++; the former exists in C. See also this question and this answer about these non-C++ containers.

Let’s compare the features of all of these. If the container you want doesn’t match one of the lines below exactly, you’ll need to implement your own and choose a name for it.

Criterion C array array vector unique_ptr valarray dynarray static_vector small_vector stable_vector
Origin/library language std std std std discarded std Boost Boost Boost
Type parameters T,N T,N T,A T T T T,C,O T,N,A,O T,A
Capacity fix time Compile Compile Never (Construct) Never Construct Compile Never Never
Size fix time Compile Compile Never N/A Never Never Construct Never Never
Size = capacity always? N/A
Storage typically on Stack Stack Heap Heap Heap Heap Stack Stack/Heap Heap
Stable iterators? N/A N/A N/A N/A N/A (✔)
Constraint on element type

Template parameter legend:

  • A for allocator
  • T for element type
  • N for size in number of elements
  • C for capacity in number of elements
  • O for options

Finally, an interesting but less popular vector-like container is the “veque”, or deque-vector amalgam.

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