`GF2::Vector` — Iterate over the Set Bits

Iterate over the elements in a bit-vector calling a function f(i) for every index i where the corresponding element is 1.

constexpr void if_set_call(std::invocable<std::size_t> auto f) const;           (1)
constexpr void reverse_if_set_call(std::invocable<std::size_t> auto f) const;   (2)

1	The iteration here is in the order `vector.first()` forward to `vector.last()`.
2	The iteration here is in the order `vector.last()` backward to `vector.first()`.

Template Parameter

Template Parameter
`std::invocable<…>`	`std::invocable<std::size_t>` is the signature for a function taking an index as its argument.
Parameters
`f`	For each set element index `pos` we will call `f(pos)`.

std::invocable<…>

std::invocable<std::size_t> is the signature for a function taking an index as its argument.

Parameters

f

For each set element index pos we will call f(pos).

Example

#include <GF2/GF2.h>
int main()
{
    GF2::Vector<> v(11, [&](size_t k) { return (k + 1) % 2; });     (1)
    std::cout << "The set indices in " << v << " are ";
    v.if_set_call([](std::size_t k) { std::cout << k << ' '; });    (2)
    std::cout << std::endl;
}

1	Creates a vector of size 11 by calling a lambda that sets all the even indices.
2	The trivial print to `std::cout` lambda only get called if the corresponding element in `v` is set.

Output

The set indices in 10101010101 are 0 2 4 6 8 10

GF2::Vector — Iterate over the Set Bits

`GF2::Vector` — Iterate over the Set Bits