beman.inplace_vector: Dynamically-resizable vector with fixed capacity

Implements

• inplace_vector P0843R14

Usage

Definition in P0843

inplace_vector is a dynamically-resizable array with capacity fixed at compile time and contiguous inplace storage, that is, the array elements are stored within the vector object itself. Its API closely resembles std::vector<T, A>, making it easy to teach and learn, and the inplace storage guarantee makes it useful in environments in which dynamic memory allocations are undesired.

Code example

#include <array>
#include <cassert>

#include <beman/inplace_vector/inplace_vector.hpp>

using namespace beman::inplace_vector;

/**
 * Generates fibonacci sequence using inplace_vector.
 * See: https://en.wikipedia.org/wiki/Fibonacci_sequence
 */
template <int Capacity> inplace_vector<int, Capacity> fibonacci_to(int num) {
  assert(num < Capacity);

  inplace_vector<int, Capacity> vec;

  constexpr static std::array<int, 2> first_two{0, 1};
  for (auto i = 0; i <= num; ++i) {
    auto new_val = i < 2 ? first_two[i] : vec[i - 1] + vec[i - 2];
    vec.push_back(new_val);
  }

  return vec;
}

How to Build

Compiler support

Building this repository requires C++17 or later.

Dependencies

TODO: tested platforms.

Instructions

Manual CMake Build

# Configure build
$ cmake -S . -B build -DCMAKE_CXX_STANDARD=20
-- The CXX compiler identification is GNU 11.4.0
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done (0.4s)
-- Generating done (0.0s)
-- Build files have been written to: /.../inplace_vector/build

# Build
$ cmake --build build
[ 50%] Building CXX object src/beman/inplace_vector/tests/CMakeFiles/beman.inplace_vector.test.dir/inplace_vector.test.cpp.o
[100%] Linking CXX executable beman.inplace_vector.test
[100%] Built target beman.inplace_vector.test

# Run tests
$ ctest --test-dir build/
Internal ctest changing into directory: /.../inplace_vector/build
Test project /.../inplace_vector/build
    Start 1: beman.inplace_vector.test
1/1 Test #1: beman.inplace_vector.test ........   Passed    0.00 sec

100% tests passed, 0 tests failed out of 1

Total Test time (real) =   0.01 sec

Development

Linting

This project use pre-commit framework for linting.

Install pre-commit

pip3 install pre-commit

pre-commit can be configured to automatically triggered before git commit, to install this functionality, run:

pre-commit install

Running pre-commit

pre-commit run --all-files

This will download and check linting rules on all files. Apart from Markdown files, pre-commit will automatically format the files to conform with linting rules in place.