OneBit

HAPI Compatibility: Works with new Check/Apply/ApplyPack API (2026-Q2)

HAPI-compatible bit manipulation components. Compose over any Unit-typed storage (hardware registers or RAM variables).

Mask descriptors

MaskVal<0x0F> // raw hex mask
Pins<1, 3, 5> // from bit positions → (1<<1)|(1<<3)|(1<<5)

Components

Bits<Unit, data> — raw storage

Innermost component. Owns a reference to a register or variable.

static Unit get() // read data
static void set(Unit v) // write data// internal — pass through chain, not filtered by Mask:
static void rawSet(Unit bits) // data |= bits
static void rawClear(Unit bits) // data &= ~bits
static void rawWrite(Unit bits, Unit mask) // data = (data & ~mask) | (bits & mask)

Mask<MaskDesc> — bit selection

Narrows get()/set() to selected bits. raw* calls pass through unchanged.

staticconstexpr Type maskBits() // compiled mask value
static Type get() // Base::get() & maskBits()
static void set(Type v) // rawWrite(v & mask, mask)

BitField<shift, size> — contiguous field, LSB-aligned

staticconstexpr Type fieldMask() // ((1<<size)-1) << shift
static Type get() // (Base::get() & fieldMask()) >> shift
static void set(Type v) // places v at bits [shift .. shift+size-1]

Inverted<MaskDesc = void> — logical inversion

// Inverted<> — invert all bits// Inverted<Pins<1,3>> — invert only selected bitsstatic Type get()
static void set(Type v)

MaskedInvert<MaskDesc> — select + invert, position-independent

static Type get() // selected bits inverted; unselected pass through
static void set(Type v)

Chain closer

BitsDef<Comp1, Comp2, ...> assembles a concrete type with no separate terminal:

using LedBit = BitsDef<Mask<Pins<5>>, Bits<uint8_t, portReg>>;
LedBit led;
led.set(led.maskBits()); // set bit 5
led.set(0); // clear bit 5

Layer order (outermost → innermost)

BitsDef [optional]
Inverted / MaskedInvert
Mask<MaskDesc> or BitField<shift,size>
Bits<Unit, data> ← always innermost