2.20. BitfieldΒΆ

Bitfields are a nameless types which represent a collection of up to 32-bit flags in a single integer:

var t : bitfield < one; two; three >

There is a shorthand type alias syntax to define a bitfield:

bitfield bits123
    one
    two
    three

typedef
    bits123 = bitfield<one; two; three> // exactly the same as the declaration above

Any two bitfields are the same type and represent 32-bit integer:

var a : bitfield<one; two; three>
var b : bitfield<one; two>
b = a

Individual flags can be read as if they were regular bool fields:

var t : bitfield < one; two; three >
assert(!t.one)

If alias is available, bitfield can be constructed via alias notation:

assert(t==bits123 three)

Bitfields can be constructed via an integer value. Limited binary logical operators are available:

var t : bitfield < one; two; three > = bitfield(1<<1) | bitfield(1<<2)
assert(!t.one && t.two && t.three)
assert("{t}"=="(two|three)")
t ^= bitfield(1<<1)