What's the result of a & b?

Question

This is awkward, but the bitwise AND operator is defined in the C++ standard as follows (emphasis mine).

The usual arithmetic conversions are performe

Answer 1

C++ Standard defines storage as a certain amount of bits. The implementation might decide what meaning to attribute to a particular bit; that being said, binary AND is supposed to work on conceptual 0s and 1s forming a particular type's representation.

3.9.1.7. (...) The representations of integral types shall define values by use of a pure binary numeration system.⁴⁹ (...)

3.9.1, footnote 49) A positional representation for integers that uses the binary digits 0 and 1, in which the values represented by successive bits are additive, begin with 1, and are multiplied by successive integral power of 2, except perhaps for the bit with the highest position

That means that for whatever physical representation used, binary AND acts according to the truth table for the AND function (for each bit number i, take bits A_i and B_i from appropriate operands and produce a value of 1 only if both are 1, otherwise produce a 0 for the bit R_i).. Resulting value is left to interpret by the implementation, but whatever is chosen, it has to be in line with other expectations with regard to other binary operations like OR and XOR.