Custom Vector Class

MyVector is a feature-complete, generic and customizable resizable array implementation in C++ that supports almost the entire C++ std::vector API.

Features

• Measurement of the execution time difference between std::vector and custom vector class
• Doxygen documentation describing each and every implemented method
• Unit testing (using googletest)

Execution time

Difference in the execution time between std::vector and MyVector using .push_back()

Data Structure	10000	100000	1000000	10000000	100000000	Total
std::vector	0.000174602s	0.00123856s	0.0125634s	0.144284s	1.37746s	1.53572s
MyVector	0.000134863s	0.00139039s	0.0136582s	0.166781s	1.58274s	1.76471s

Examples

.push_back()

Appends the given element value to the end of the container

Method

void push_back(const T &val) {
    if (avail == limit)
        grow();
    unchecked_append(val);
}

Usage example

MyVector<int> example;

for(int i = 0; i < 5; ++i)
    example.push_back(i);

std::cout << "Vector elements: "; // 0  1  2  3  4
for (int i: example) 
    std::cout << i << ' ';


std::cout << "Vector size: " << example.size() << std::endl; // 5
std::cout << "Vector capacity: " << example.capacity() << std::endl; // 8

.pop_back()

Removes the last element of the container

Method

void pop_back() {
    iterator new_avail = avail;
    alloc.destroy(--new_avail);
    avail = new_avail;
}

Usage example

MyVector<int> example {1,2,3,4,5};

example.pop_back();

std::cout << "Vector size: " << example.size() << std::endl; // 4
std::cout << "Vector capacity: " << example.capacity() << std::endl; // 5

.shrink_to_fit()

Requests the removal of unused capacity

Method

void shrink_to_fit() { 
    if (limit > avail) 
        limit = avail; 
}

Usage example

MyVector<int> example {1,2,3,4,5};

example.reserve(500);

std::cout << "Vector size: " << example.size() << std::endl; // 5
std::cout << "Vector capacity: " << example.capacity() << std::endl; // 500

example.shrink_to_fit();

std::cout << "Vector size: " << example.size() << std::endl; // 5
std::cout << "Vector capacity: " << example.capacity() << std::endl; // 5

Project Setup

Navigate to the directory of choice and clone the project

git clone https://github.com/tmneth/vector.git

Initialise and update google test submodules

git submodule init
git submodule update

Compile the program

cd vector/src && g++ 'main.cpp' -o 'main' && ./main