WillisMedwell / wm

Collection of everyday helpers for C++

wm

Header only libraries for everyday C++ use.

• wm
  • Sov (Structure of Vectors)
  • Functors
  • SplitByElement
• Installation
  • Manual
  • CMake

Sov (Structure of Vectors)

Like a structure of arrays but with reallocation like std::vector. All memory is in one block making it very cache friendly.

A live comparison between an object orientated approach and data orientated approach using std::vector vs wm::Sov can be found here.

Usage

wm::Sov<uint8_t, std::string, uint16_t> sov;

sov.pushBack(0, "first", 1);
sov.pushBack(0, "second", 2);

// get individual field (like using std::get<>)
for (auto e : sov.field<0>()) {
    std::cout << (int)e << ' ';
}
for (auto e : sov.field<uint16_t>()) {
    std::cout << (int)e << ' ';
}

// range based loop (takes it as a reference)
for (const auto& [a, b, c] : sov) {
    std::cout << "(" << (int)a << ", " << b << ", " << (int)c << ")\n";
}

// reference to elements
auto [field_1, field_2, field_3] = sov[2];

Functors

Honestly cannot believe the std doesn't support these. Literally blows my mind.

Usage

std::vector<int> range = { 1, 2, 3, 4, 5, 6};

std::ranges::find_if(range, wm::IsEqualTo(4));
std::ranges::find_if(range, wm::IsNotEqualTo(1));
std::ranges::any_of(range, wm::IsGreaterThan(5));
std::ranges::all_of(range, wm::IsLessThan(1));

SplitByElement

Takes a contiguous range and returns spans into that range with no copying.

• Range based loops = lazily evaluated.
• Indexing = on first index, are evaluated.

std::views::split & std::views::lazy_split are too temperamental in my opinion.

Usage

std::string_view sentence = " I went for a run yesterday ";
for(std::span<const char> word_data : wm::SplitByElement{sentence, ' ' })
{
    std::string_view word { word_data.begin(), word_data.end() };
    std::cout << word << ',';
}
// "I,went,for,a,run,yesterday,"

std::vector<int> nums = { 2, 1, 2, 2, 3, 4, 2 };

num_grouping = wm::SplitByElement{nums, 2};

std::span<int> num_group0 = num_grouping[0];
// [ 1 ]
std::span<int> num_group1 = num_grouping[1];
// [ 3, 4 ]

Installation

Manual

Download the headers from the Releases.

CMake

You can use the CMake fetching module to do it all for you.

# Cmake's fetch module.
include(FetchContent)

# Fetch the ZIP file containing the headers. Lets you always have the latest release.
FetchContent_Declare(
  wm_headers
  URL https://github.com/WillisMedwell/wm/releases/download/Headers/headers.zip
)

FetchContent_GetProperties(wm_headers)
FetchContent_Populate(wm_headers)
set(WM_HEADERS_DIR ${wm_headers_SOURCE_DIR}) 

# Add to your include list.
target_include_directories(${CMAKE_PROJECT_NAME}
    PRIVATE
        ${PROJECT_SOURCE_DIR}/include
        ${WM_HEADERS_DIR}
)

Then using it is as simple as...

#include "wm/Sov.hpp"

int main()
{
    wm::Sov<int, int, int> foos; 
}