/*
* Copyright (c) 2024 Andrew Rowan Barlow. Licensed under the EUPL-1.2
* or later. You may obtain a copy of the licence at
* https://joinup.ec.europa.eu/collection/eupl/eupl-text-eupl-12. A copy
* of the EUPL-1.2 licence in English is given in LICENCE.txt which is
* found in the root directory of this repository.
*
* Author: Andrew Rowan Barlow <a.barlow.dev@gmail.com>
*/
/// Distinguishes observable and non-observable quantities.
///
/// For example, this will distinguish the retrieval of a superposition (that cannot be measured
/// directly), and the state resulting from the collapse of a superposition upon measurement. See
/// [crate::SimulatedCircuit::measure_all] and [crate::SimulatedCircuit::get_state] for examples.