How can I convert std::vector to a vector of pairs std::vector> using an STL algorithm?

I have a vector of integers:

std::vector values = {1,2,3,4,5,6,7,8,9,10};

Given that values.size() will always be even.

I simply want to convert the adjacent elements into a pair, like this:

std::vector<std::pair<int,int>> values = { {1,2}, {3,4} , {5,6}, {7,8} ,{9,10} };

I.e., the two adjacent elements are joined into a pair.

What STL algorithm can I use to easily achieve this? Is it possible to achieve this through some standard algorithms?

Of course, I can easily write an old-school indexed for loop to achieve that. But I want to know what the simplest solution could look like using range-based for loops or any other STL algorithm, like std::transform, etc.

Answer 1
Once we have C++23’s extension to , you can get most of the way there with std::ranges::views::chunk, although that produces subranges, not pairs.

#include
#include
#include </code>

int main()
{
std::vector values = {1,2,3,4,5,6,7,8,9,10};
auto chunk_to_pair = [](auto chunk)
{
return std::pair(*chunk.begin(), *std::next(chunk.begin()));
};
for (auto [first, second] : values | std::ranges::views::chunk(2) | std::ranges::views::transform(chunk_to_pair))
{
std::cout &lt;&lt; first &lt;&lt; second &lt;&lt; std::endl;
}
}

Alternatively, you could achieve a similar result by ziping a pair of strided views

#include
#include
#include

int main()
{
std::vector values = {1,2,3,4,5,6,7,8,9,10};
auto odds = values | std::ranges::views::drop(0) | std::ranges::views::stride(2);
auto evens = values | std::ranges::views::drop(1) | std::ranges::views::stride(2);
for (auto [first, second] : std::ranges::views::zip(odds, evens))
{
std::cout << first << second << std::endl;
}
}