Iterating over vector in C++

Benchmark iterating over a vector (heap memory) using various techniques.

sample1

Iterate over a vector using a simple for loop:

for (auto i = 0; i < a.size(); ++i)

sample2

Iterate over a vector using a backward for loop:

for (auto i = a.size() - 1; i >= 0; --i)

sample3

Iterate over a vector using a foreach loop:

for (auto i : a)

sample1_suffix

Use suffix / postfix increment operator:

for (auto i = 0; i < a.size(); i++)

sample2_suffix

Use suffix / postfix decrement operator:

for (auto i = a.size() - 1; i >= 0; i--)