Enable usage of optional in contexts where containers can be used (in range-based for loop, in standard algorithms, generic template functions that receive iterators or range as arguments).
#include <iostream>
#include <numeric>
#include "owi/optional.hpp"
int main(void)
{
owi::optional<int> opt{42};
owi::optional<int> empty;
std::cout << "==== RANGE-BASED FOR LOOP ====\n";
for (int i : opt)
std::cout << i << std::endl;
std::cout << "\n==== RANGE-BASED FOR LOOP for empty optional ====\n";
for (int i : empty)
std::cout << i << std::endl;
std::cout << "\n==== Standard algorigms with optional ====\n";
std::cout << "Sum of elements: " << std::accumulate(opt.cbegin(), opt.cend(), 0) << std::endl;
}Output:
==== RANGE-BASED FOR LOOP ====
42
==== RANGE-BASED FOR LOOP for empty optional ====
==== Standard algorigms with optional ====
Sum of elements: 42
The class is licensed under the MIT License:
Copyright © 2021 Seleznev Anton
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