STLAlgorithms.md

Standard Library Algorithms

Not everything is a member function

Collections, Algorithms, Iterators

Say what you mean

Why make someone puzzle out your code?

Algorithms have names that are clues

Using sort, find and generate are much more expressive.

Algorithm Documentation

Less Fuss Over Style

i++ ++i In the for statement? In the loop body?

Iterators vs. random access[]

Names for indices, iterators, etc.

vector<int> v;

// instead of a traditional loop for filling a vector
for (int i = 0; i < 5; i++)
{
    v.push_back(i);
}

int i = 0;
std::generate_n(std::back_inserter(v), 5, [&]() {return i++;} );

// another example accumulating elements
int total = 0;
total = std::accumulate(begin(v), end(v), 0);

int count3 = std::coud(begin(v), end(v), 3); 

Avoiding errors

Trying to remove elements from a vector with iterators this way will invalidate the iterator.

vector<int> v {0, 1, 2, 3, 4, 0, 1, 2, 3, 4};

for (auto it = begin(v); it != end(v); it++)
{
    if (*it == 3)
    {
        v.erase(it);
    }
}

One solution with algorithms remove_if returns an iterator, which you can use later with erase to remove the desired items.

vector<int> v {0, 1, 2, 3, 4, 0, 1, 2, 3, 4};

auto endV = std::remove_if(begin(v), end(v), [](int elem) {return (elem == 3); });
v.erase(endV, end(v));