ABool (JIT)¶

Overview¶

template <class Scalar, std::size_t N = 1> class ABool;

ABool is a helper type for trackable booleans in JIT-enabled builds. It supports:

comparisons that can be recorded into a JITGraph when a JITCompiler is active
conditional selection via If(trueVal, falseVal)

Compile-time feature flag

This API is only available when XAD is compiled with XAD_ENABLE_JIT.

Convenience Typedef¶

using ADBool = ABool<double, 1>;

Convenience alias for the common case of double scalar type with scalar mode (N=1).

Constructor¶

explicit ABool(bool b = false);

Constructs an ABool from a plain bool. The result has no JIT slot (passive only).

Member Functions¶

Function	Returns	Description
`passive()`	`bool`	Returns the passive (C++) boolean value
`slot()`	`slot_type`	Returns the JIT graph slot ID, or INVALID_SLOT if none
`hasSlot()`	`bool`	Returns true if this ABool has a valid JIT slot
`operator bool()`	`bool`	Implicit conversion to bool (returns passive value)

Conditional Selection¶

Function	Description
`If(trueVal, falseVal)`	Member: returns trueVal if true, falseVal otherwise
`ABool::If(cond, trueVal, falseVal)`	Static: equivalent to `cond.If(trueVal, falseVal)`

When a JIT compiler is active and the ABool has a slot, an If node is recorded in the graph, allowing the branch to vary at runtime. If no JIT is active (e.g., Tape mode), this behaves like a normal conditional.

Comparison Functions¶

The following free functions in the xad namespace create ABool values from comparisons. When a JIT compiler is active, comparison nodes are recorded in the graph. Otherwise, they return a passive ABool.

All functions have two overloads: (AReal, AReal) and (AReal, Scalar).

Function	Description	Equivalent
`less(a, b)`	Returns true if a < b	`a < b`
`greater(a, b)`	Returns true if a > b	`a > b`
`lessEqual(a, b)`	Returns true if a <= b	`a <= b`
`greaterEqual(a, b)`	Returns true if a >= b	`a >= b`