GF2::Vector — Binary Shift Operators
Methods to perform binary left and right shifts for the elements in a bit-vector where zeros are shifted in as needed.
constexpr Vector &operator<<=(std::size_t p); (1)
constexpr Vector &operator>>=(std::size_t p); (2)
constexpr Vector operator<<(std::size_t p) const; (3)
constexpr Vector operator>>(std::size_t p) const; (4)| 1 | Left-shift this bit-vector p places (zeros are shifted in). |
| 2 | Right-shift this bit-vector p places (zeros are shifted in). |
| 3 | Returns a bit-vector that is this one left shifted by p places |
| 4 | Returns a bit-vector that is this one right shifted by p places |
The first two methods are destructive (i.e. operate in-place) and return a reference to *this so can be chained with other calls.
Example
#include <GF2/GF2.h>
int main()
{
GF2::Vector<> v("111111111111");
std::cout << "Left shift (vectors printed here in bit-order!):\n"; (1)
std::cout << "v: " << v.to_bit_order() << '\n';
std::cout << "v << 1: " << (v << 1).to_bit_order() << '\n';
std::cout << "v << 4: " << (v << 4).to_bit_order() << '\n';
std::cout << "v << 9: " << (v << 9).to_bit_order() << '\n';
std::cout << "v << 13: " << (v << 13).to_bit_order() << '\n';
std::cout << std::endl;
std::cout << "Right shift (vectors printed here in bit-order!):\n";
std::cout << "v: " << v.to_bit_order() << '\n';
std::cout << "v >> 1: " << (v >> 1).to_bit_order() << '\n';
std::cout << "v >> 4: " << (v >> 4).to_bit_order() << '\n';
std::cout << "v >> 9: " << (v >> 9).to_bit_order() << '\n';
std::cout << "v >> 13: " << (v >> 13).to_bit_order() << '\n';
std::cout << std::endl;
}| 1 | It is more intuitive to see the effect of left & right shifts if the vectors are printed in bit-order where the the least significant bit v[0] is on the right. |
Output
Left shift (vectors printed here in bit-order!):
v: 111111111111
v << 1: 111111111110
v << 4: 111111110000
v << 9: 111000000000
v << 13: 000000000000
Right shift (vectors printed here in bit-order!):
v: 111111111111
v >> 1: 011111111111
v >> 4: 000011111111
v >> 9: 000000000111
v >> 13: 000000000000