autopas::utils Namespace Reference

In this namespace some helper classes and functions can be found used inside of AutoPas. More...

Namespaces
namespace	ArrayMath
	Namespace to handle mathematical operations of std::array.
namespace	ArrayUtils
	In this namespace some helper functions for std::array can be found.
namespace	AutoPasConfigurationCommunicator
	Provides several functions for handling configurations among mpi ranks.
namespace	CompileInfo
	Namespace for functions that provide information about what the code was compiled with.
namespace	is_container_impl
	Collection of structs that define what we consider a container.
namespace	NumParticlesEstimator
	Functions to estimate numbers of particles.
namespace	quaternion
	Array utils specifically for handling quaternions.
namespace	StringUtils
	Some functions to parse enums from (input-) strings.
namespace	ThreeDimensionalMapping
	Namespace to handle the conversion between one dimensional and three dimensional indices.
namespace	TupleUtils
	In this namespace some helper functions for std::tuple can be found.

Classes
class	DataLayoutConverter
	This converts cells to the target data Layout using the given functor. More...
class	EnergySensor
	Measure the energy consumption of a simulation on multiple hardwares. More...
class	ExceptionHandler
	Defines and handles the throwing and printing of exceptions. More...
struct	is_shared_ptr
	Type trait to determine if a type is a shared pointer at compile time. More...
struct	is_shared_ptr< std::shared_ptr< T > >
	True specialization for shared_ptr. More...
struct	is_smart_ptr
	Type trait to determine if a type is a smart pointer at compile time. More...
struct	is_smart_ptr< std::shared_ptr< T > >
	True specialization for shared_ptr. More...
struct	is_smart_ptr< std::unique_ptr< T > >
	True specialization for unique_ptr. More...
struct	is_smart_ptr< std::weak_ptr< T > >
	True specialization for weak_ptr. More...
struct	is_unique_ptr
	Type trait to determine if a type is a unique pointer at compile time. More...
struct	is_unique_ptr< std::unique_ptr< T > >
	True specialization for unique_ptr. More...
class	ParticleBinStructure
	Particle-counting bin structure. More...
struct	ParticleTypeTrait
	ParticleTypeTrait class. More...
struct	ParticleTypeTrait< autopas::AutoPas< Particle_T > >
	Specialization for the AutoPas class. More...
struct	ParticleTypeTrait< std::vector< ParticleCell > >
	Specialization for vectors of ParticleCells. More...
class	SoAStorage
	SoAStorage is a helper to access the stored SoA's. More...
struct	SoAType
	Helper struct to get a the SoAType. More...
class	Timer
	Timer class to stop times. More...
class	TraceTimer
	A wrapper around autopas::utils::Timer that only compiles implementation logic if AUTOPAS_ACTIVE_LEVEL is set to TRACE. More...

Concepts
concept	ContainerType
	Concept to check if something is a container (vector, array or set).

Typedefs
template<typename FunctorT >
using	isPairwiseFunctor = decltype(isPairwiseFunctorImpl(std::declval< FunctorT >()))
	Check whether a Functor Type is inheriting from PairwiseFunctor.
template<typename FunctorT >
using	isTriwiseFunctor = decltype(isTriwiseFunctorImpl(std::declval< FunctorT >()))
	Check whether a Functor Type is inheriting from TriwiseFunctor.
template<typename T >
using	optRef = std::optional< std::reference_wrapper< T > >
	Short alias for std::optional<std::reference_wrapper<T>>
using	bestSteadyClock = std::conditional_t< std::chrono::high_resolution_clock::is_steady, std::chrono::high_resolution_clock, std::chrono::steady_clock >
	high_resolution_clock is not guaranteed to be monotonous in time, which can lead to negative duration times.

Enumerations
enum	ExceptionBehavior { ignore , throwException , printAbort , printCustomAbortFunction }
	Enum that defines the behavior of the expection handling. More...

Functions
template<class T >
std::size_t	hashValue (const T &value)
	Hash of a single value.
template<class... Values_T>
std::size_t	hashCombine (const Values_T &...values)
	Combines the hashes of an arbitrary number of values into one hash.
template<typename T >
bool	inBox (const std::array< T, 3 > &position, const std::array< T, 3 > &low, const std::array< T, 3 > &high)
	Checks if position is inside of a box defined by low and high.
template<typename T >
bool	notInBox (const std::array< T, 3 > &position, const std::array< T, 3 > &low, const std::array< T, 3 > &high)
	Checks if position is not inside of a box defined by low and high.
template<typename T >
bool	boxesOverlap (const std::array< T, 3 > &boxALow, const std::array< T, 3 > &boxAHigh, const std::array< T, 3 > &boxBLow, const std::array< T, 3 > &boxBHigh)
	Checks if two boxes have overlap.
template<typename F >
decltype(auto)	withStaticBool (bool theBool, F &&func)
	Function to execute the code passed in the lambda with a static bool.

Detailed Description

In this namespace some helper classes and functions can be found used inside of AutoPas.

These classes reside mostly in the utils directory. However, most commonly used function inside the utils directory might not be in the utils namespace.

Typedef Documentation

bestSteadyClock

using autopas::utils::bestSteadyClock = typedef std::conditional_t<std::chrono::high_resolution_clock::is_steady, std::chrono::high_resolution_clock, std::chrono::steady_clock>

high_resolution_clock is not guaranteed to be monotonous in time, which can lead to negative duration times.

Swap to steady_clock then, which is usually the same precision or precise enough.

isPairwiseFunctor

template<typename FunctorT >

using autopas::utils::isPairwiseFunctor = typedef decltype(isPairwiseFunctorImpl(std::declval<FunctorT>()))

Check whether a Functor Type is inheriting from PairwiseFunctor.

Template Parameters

FunctorT

isTriwiseFunctor

template<typename FunctorT >

using autopas::utils::isTriwiseFunctor = typedef decltype(isTriwiseFunctorImpl(std::declval<FunctorT>()))

Check whether a Functor Type is inheriting from TriwiseFunctor.

Template Parameters

FunctorT

Enumeration Type Documentation

ExceptionBehavior

enum autopas::utils::ExceptionBehavior

Enum that defines the behavior of the expection handling.

Enumerator
ignore	Ignore all exceptions.
throwException	Throw the exception.
printAbort	Print the exception and.
printCustomAbortFunction	Print the exception and call a custom abort function.

Function Documentation

boxesOverlap()

template<typename T >

bool autopas::utils::boxesOverlap	(	const std::array< T, 3 > &	boxALow,
		const std::array< T, 3 > &	boxAHigh,
		const std::array< T, 3 > &	boxBLow,
		const std::array< T, 3 > &	boxBHigh
	)

Checks if two boxes have overlap.

If the boxes touch (= exact same floating point values), they are not considered to have overlap.

Template Parameters

T

Parameters

boxALow
boxAHigh
boxBLow
boxBHigh

Returns

hashCombine()

template<class... Values_T>

std::size_t autopas::utils::hashCombine

(

const Values_T &...

values

)

Combines the hashes of an arbitrary number of values into one hash.

Equivalent to repeated application of boost::hash_combine (Boost >= 1.81), i.e. seed = mix(seed + 0x9e3779b9 + hashValue(value)).

The mixer is the xmxmx bit mixer used by boost::hash_combine (boost/container_hash/detail/hash_mix.hpp). It is reproduced here instead of pulling in Boost, and as we use this for ease and not in performance critical situations, we do not care so much about getting the latest version from Boost.

The parameters used are those from Jon Maiga's implementation (https://jonkagstrom.com/mx3/mx3_rev2.html).

Template Parameters

Values_T

Types of the values to hash.

Parameters

values

Values to hash.

Returns

Combined hash.

hashValue()

template<class T >

std::size_t autopas::utils::hashValue

(

const T &

value

)

Hash of a single value.

Uses std::hash if it is specialized for T (arithmetic types, enums, strings, pointers, ...) and otherwise falls back to a static_cast to std::size_t. The latter covers AutoPas Option types, which implicitly convert to their underlying enum.

Template Parameters

T	Type of the value.

Parameters

value

Value to hash.

Returns

Hash of value.

inBox()

template<typename T >

bool autopas::utils::inBox	(	const std::array< T, 3 > &	position,
		const std::array< T, 3 > &	low,
		const std::array< T, 3 > &	high
	)

Checks if position is inside of a box defined by low and high.

The lower corner is included in, the upper is excluded from the box. i.e. [low[0], high[0]) x [low[1], high[1]) x [low[2], high[2])

Template Parameters

T	the type of floating point check

Parameters

position	the position that should be checked
low	the lower corner of the box (inclusive)
high	the upper corner of the box (exclusive)

Returns

true if position is inside the box, false otherwise

notInBox()

template<typename T >

bool autopas::utils::notInBox	(	const std::array< T, 3 > &	position,
		const std::array< T, 3 > &	low,
		const std::array< T, 3 > &	high
	)

Checks if position is not inside of a box defined by low and high.

The lower corner is included in, the upper is excluded from the box. i.e. [low[0], high[0]) x [low[1], high[1]) x [low[2], high[2])

Template Parameters

T	the type of floating point check

Parameters

position	the position that should be checked
low	the lower corner of the box (inclusive)
high	the upper corner of the box (exclusive)

Returns

true if position is not inside the box, false otherwise

withStaticBool()

template<typename F >

decltype(auto) autopas::utils::withStaticBool	(	bool	theBool,
		F &&	func
	)

Function to execute the code passed in the lambda with a static bool.

The static value of the boolean will be passed using the first argument of function.

Parameters

theBool	The bool that should be used statically.
func	Function to be called, should accept a static bool type, e.g., [&](auto theBool){};

Returns

Returns whatever func returns.