Kokkos_Pair.hpp File Reference

Declaration and definition of Kokkos::pair. More...

#include <Kokkos_Macros.hpp>
#include <Kokkos_Swap.hpp>
#include <utility>

Go to the source code of this file.

Classes
struct	Kokkos::pair< T1, T2 >
	Replacement for std::pair that works on CUDA devices. More...

Namespaces
namespace	Kokkos::Impl
	ScopeGuard Some user scope issues have been identified with some Kokkos::finalize calls; ScopeGuard aims to correct these issues.

Functions
template<class T1 , class T2 >
KOKKOS_FORCEINLINE_FUNCTION constexpr bool	Kokkos::operator== (const pair< T1, T2 > &lhs, const pair< T1, T2 > &rhs)
	Equality operator for Kokkos::pair.
template<class T1 , class T2 >
KOKKOS_FORCEINLINE_FUNCTION constexpr bool	Kokkos::operator!= (const pair< T1, T2 > &lhs, const pair< T1, T2 > &rhs)
	Inequality operator for Kokkos::pair.
template<class T1 , class T2 >
KOKKOS_FORCEINLINE_FUNCTION constexpr bool	Kokkos::operator< (const pair< T1, T2 > &lhs, const pair< T1, T2 > &rhs)
	Less-than operator for Kokkos::pair.
template<class T1 , class T2 >
KOKKOS_FORCEINLINE_FUNCTION constexpr bool	Kokkos::operator<= (const pair< T1, T2 > &lhs, const pair< T1, T2 > &rhs)
	Less-than-or-equal-to operator for Kokkos::pair.
template<class T1 , class T2 >
KOKKOS_FORCEINLINE_FUNCTION constexpr bool	Kokkos::operator> (const pair< T1, T2 > &lhs, const pair< T1, T2 > &rhs)
	Greater-than operator for Kokkos::pair.
template<class T1 , class T2 >
KOKKOS_FORCEINLINE_FUNCTION constexpr bool	Kokkos::operator>= (const pair< T1, T2 > &lhs, const pair< T1, T2 > &rhs)
	Greater-than-or-equal-to operator for Kokkos::pair.
template<class T1 , class T2 >
KOKKOS_FORCEINLINE_FUNCTION constexpr pair< T1, T2 >	Kokkos::make_pair (T1 x, T2 y)
	Return a new pair.
template<class T1 , class T2 >
KOKKOS_FORCEINLINE_FUNCTION pair< T1 &, T2 & >	Kokkos::tie (T1 &x, T2 &y)
	Return a pair of references to the input arguments.

Detailed Description

Declaration and definition of Kokkos::pair.

This header file declares and defines Kokkos::pair and its related nonmember functions.

Definition in file Kokkos_Pair.hpp.

Function Documentation

operator==()

template<class T1 , class T2 >

KOKKOS_FORCEINLINE_FUNCTION constexpr bool Kokkos::operator== ( const pair< T1, T2 > &  lhs, const pair< T1, T2 > &  rhs  )

constexpr

Equality operator for Kokkos::pair.

Definition at line 322 of file Kokkos_Pair.hpp.

operator!=()

template<class T1 , class T2 >

KOKKOS_FORCEINLINE_FUNCTION constexpr bool Kokkos::operator!= ( const pair< T1, T2 > &  lhs, const pair< T1, T2 > &  rhs  )

constexpr

Inequality operator for Kokkos::pair.

Definition at line 329 of file Kokkos_Pair.hpp.

operator<()

template<class T1 , class T2 >

KOKKOS_FORCEINLINE_FUNCTION constexpr bool Kokkos::operator< ( const pair< T1, T2 > &  lhs, const pair< T1, T2 > &  rhs  )

constexpr

Less-than operator for Kokkos::pair.

Definition at line 336 of file Kokkos_Pair.hpp.

operator<=()

template<class T1 , class T2 >

KOKKOS_FORCEINLINE_FUNCTION constexpr bool Kokkos::operator<= ( const pair< T1, T2 > &  lhs, const pair< T1, T2 > &  rhs  )

constexpr

Less-than-or-equal-to operator for Kokkos::pair.

Definition at line 344 of file Kokkos_Pair.hpp.

operator>()

template<class T1 , class T2 >

KOKKOS_FORCEINLINE_FUNCTION constexpr bool Kokkos::operator> ( const pair< T1, T2 > &  lhs, const pair< T1, T2 > &  rhs  )

constexpr

Greater-than operator for Kokkos::pair.

Definition at line 351 of file Kokkos_Pair.hpp.

operator>=()

template<class T1 , class T2 >

KOKKOS_FORCEINLINE_FUNCTION constexpr bool Kokkos::operator>= ( const pair< T1, T2 > &  lhs, const pair< T1, T2 > &  rhs  )

constexpr

Greater-than-or-equal-to operator for Kokkos::pair.

Definition at line 358 of file Kokkos_Pair.hpp.

make_pair()

template<class T1 , class T2 >

KOKKOS_FORCEINLINE_FUNCTION constexpr pair< T1, T2 > Kokkos::make_pair ( T1  x, T2  y  )

constexpr

Return a new pair.

This is a "nonmember constructor" for Kokkos::pair. It works just like std::make_pair.

Definition at line 368 of file Kokkos_Pair.hpp.

tie()

template<class T1 , class T2 >

KOKKOS_FORCEINLINE_FUNCTION pair< T1 &, T2 & > Kokkos::tie	(	T1 &	x,
		T2 &	y
	)

Return a pair of references to the input arguments.

This compares to std::tie (new in C++11). You can use it to assign to two variables at once, from the result of a function that returns a pair. For example (device and host attributes omitted for brevity):

// Declaration of the function to call.
// First return value: operation count.
// Second return value: whether all operations succeeded.
Kokkos::pair<int, bool> someFunction ();
 
// Code that uses Kokkos::tie.
int myFunction () {
  int count = 0;
  bool success = false;
 
  // This assigns to both count and success.
  Kokkos::tie (count, success) = someFunction ();
 
  if (! success) {
    // ... Some operation failed;
    //     take corrective action ...
  }
  return count;
}

The line that uses tie() could have been written like this:

Kokkos::pair<int, bool> result = someFunction ();
count = result.first;
success = result.second;

Using tie() saves two lines of code and avoids a copy of each element of the pair. The latter could be significant if one or both elements of the pair are more substantial objects than int or bool.

Definition at line 412 of file Kokkos_Pair.hpp.