fold.hpp#

See Public API for a list of names and headers that are part of the public HPX API.

namespace hpx

namespace lcos

Functions

template<typename Action, typename FoldOp, typename Init, typename ArgN, ...> hpx::future< decltype(Action(hpx::id_type, ArgN,...))> fold (std::vector< hpx::id_type > const &ids, FoldOp &&fold_op, Init &&init, ArgN argN,...)

Perform a distributed fold operation.

The function hpx::lcos::fold performs a distributed folding operation over results returned from action invocations on a given set of global identifiers. The action can be either a plain action (in which case the global identifiers have to refer to localities) or a component action (in which case the global identifiers have to refer to instances of a component type which exposes the action.

Note

The type of the initial value must be convertible to the result type returned from the invoked action.

Parameters

ids – [in] A list of global identifiers identifying the target objects for which the given action will be invoked.
fold_op – [in] A binary function expecting two results as returned from the action invocations. The function (or function object) is expected to return the result of the folding operation performed on its arguments.
init – [in] The initial value to be used for the folding operation
argN – [in] Any number of arbitrary arguments (passed by value, by const reference or by rvalue reference) which will be forwarded to the action invocation.

Returns

This function returns a future representing the result of the overall folding operation.

template<typename Action, typename FoldOp, typename Init, typename ArgN, ...> hpx::future< decltype(Action(hpx::id_type, ArgN,..., std::size_t))> fold_with_index (std::vector< hpx::id_type > const &ids, FoldOp &&fold_op, Init &&init, ArgN argN,...)

Perform a distributed folding operation.

The function hpx::lcos::fold_with_index performs a distributed folding operation over results returned from action invocations on a given set of global identifiers. The action can be either plain action (in which case the global identifiers have to refer to localities) or a component action (in which case the global identifiers have to refer to instances of a component type which exposes the action.

The function passes the index of the global identifier in the given list of identifiers as the last argument to the action.

Note

The type of the initial value must be convertible to the result type returned from the invoked action.

Parameters

ids – [in] A list of global identifiers identifying the target objects for which the given action will be invoked.
fold_op – [in] A binary function expecting two results as returned from the action invocations. The function (or function object) is expected to return the result of the folding operation performed on its arguments.
init – [in] The initial value to be used for the folding operation
argN – [in] Any number of arbitrary arguments (passed by value, by const reference or by rvalue reference) which will be forwarded to the action invocation.

Returns

This function returns a future representing the result of the overall folding operation.

template<typename Action, typename FoldOp, typename Init, typename ArgN, ...> hpx::future< decltype(Action(hpx::id_type, ArgN,...))> inverse_fold (std::vector< hpx::id_type > const &ids, FoldOp &&fold_op, Init &&init, ArgN argN,...)

Perform a distributed inverse folding operation.

The function hpx::lcos::inverse_fold performs an inverse distributed folding operation over results returned from action invocations on a given set of global identifiers. The action can be either a plain action (in which case the global identifiers have to refer to localities) or a component action (in which case the global identifiers have to refer to instances of a component type which exposes the action.

Note

The type of the initial value must be convertible to the result type returned from the invoked action.

Parameters

ids – [in] A list of global identifiers identifying the target objects for which the given action will be invoked.
fold_op – [in] A binary function expecting two results as returned from the action invocations. The function (or function object) is expected to return the result of the folding operation performed on its arguments.
init – [in] The initial value to be used for the folding operation
argN – [in] Any number of arbitrary arguments (passed by value, by const reference or by rvalue reference) which will be forwarded to the action invocation.

Returns

This function returns a future representing the result of the overall folding operation.

template<typename Action, typename FoldOp, typename Init, typename ArgN, ...> hpx::future< decltype(Action(hpx::id_type, ArgN,..., std::size_t))> inverse_fold_with_index (std::vector< hpx::id_type > const &ids, FoldOp &&fold_op, Init &&init, ArgN argN,...)

Perform a distributed inverse folding operation.

The function hpx::lcos::inverse_fold_with_index performs an inverse distributed folding operation over results returned from action invocations on a given set of global identifiers. The action can be either plain action (in which case the global identifiers have to refer to localities) or a component action (in which case the global identifiers have to refer to instances of a component type which exposes the action.

The function passes the index of the global identifier in the given list of identifiers as the last argument to the action.

Note

The type of the initial value must be convertible to the result type returned from the invoked action.

Parameters

ids – [in] A list of global identifiers identifying the target objects for which the given action will be invoked.
fold_op – [in] A binary function expecting two results as returned from the action invocations. The function (or function object) is expected to return the result of the folding operation performed on its arguments.
init – [in] The initial value to be used for the folding operation
argN – [in] Any number of arbitrary arguments (passed by value, by const reference or by rvalue reference) which will be forwarded to the action invocation.

Returns

This function returns a future representing the result of the overall folding operation.