nros::Client< S > Class Template Reference

#include <client.hpp>

Public Types
using	RequestType = typename S::Request
using	ResponseType = typename S::Response
using	TypedResponseFn = void(*)(const ResponseType &response)
using	TypedResponseFnWithCtx = void(*)(const ResponseType &response, void *ctx)

Public Member Functions
Result	async_send_request (const RequestType &req)
Result	call (const RequestType &req, ResponseType &resp, uint32_t timeout_ms=5000)
	Client ()
	Client (Client &&other)
size_t	handle_id () const
bool	is_valid () const
	Check if the client is initialized and valid.
Client &	operator= (Client &&other)
Future< ResponseType >	send_request (const RequestType &req)
int	server_available () const
	~Client ()

Friends
class	Node

Detailed Description

template<typename S>
class nros::Client< S >

Typed service client for a ROS 2 service.

Mirrors rclcpp::Client<S>. The service type S must provide nested Request and Response types with TYPE_NAME, TYPE_HASH, SERIALIZED_SIZE_MAX, ffi_serialize(), and ffi_deserialize().

Usage (async – preferred):

nros::Client<example_interfaces::srv::AddTwoInts> client;
NROS_TRY(node.create_client(client, "/add_two_ints"));
auto fut = client.send_request(req);
ResponseType resp;
NROS_TRY(fut.wait(executor.handle(), 5000, resp));

Member Typedef Documentation

RequestType

template<typename S >

using nros::Client< S >::RequestType = typename S::Request

ResponseType

template<typename S >

using nros::Client< S >::ResponseType = typename S::Response

TypedResponseFn

template<typename S >

using nros::Client< S >::TypedResponseFn = void (*)(const ResponseType& response)

Phase 189.M3.3.f — typed response-handler signatures for the callback-style client (rclcpp async dispatch). The handler runs during spin_once when a reply arrives for a request sent via async_send_request.

TypedResponseFnWithCtx

template<typename S >

using nros::Client< S >::TypedResponseFnWithCtx = void (*)(const ResponseType& response, void* ctx)

Constructor & Destructor Documentation

~Client()

template<typename S >

nros::Client< S >::~Client ( )

inline

Destructor – releases service client resources.

Future-style clients own an RmwServiceClient in storage_; callback-style clients (M3.3.f) are owned by the executor arena, so the dtor must NOT touch storage_ for them.

Client() [1/2]

template<typename S >

nros::Client< S >::Client ( Client< S > &&  other )

inline

Client() [2/2]

template<typename S >

nros::Client< S >::Client ( )

inline

Default constructor – creates an uninitialized service client. Use Node::create_client() to initialize.

Member Function Documentation

async_send_request()

template<typename S >

Result nros::Client< S >::async_send_request ( const RequestType &  req )

inline

Phase 189.M3.3.f — callback-style async send. Only valid on a callback-style client (created via the create_client(out, name, callback, ...) overload); the reply is delivered to the registered response handler during spin_once (no Future). Returns immediately after sending.

call()

template<typename S >

Result nros::Client< S >::call ( const RequestType &  req, ResponseType &  resp, uint32_t  timeout_ms = 5000  )

inline

Send a request and block until a reply is received.

Spins the executor internally (like the runtime's Promise::wait). Never calls zpico_get — all I/O is driven by spin_once.

Parameters

req	Request to send.
resp	Output response struct (filled on success).
timeout_ms	Maximum wait time (default 5000ms).

Returns

Result indicating success, timeout, or failure.

handle_id()

template<typename S >

size_t nros::Client< S >::handle_id ( ) const

inline

Executor handle for the callback-style client (Phase 189.M3.3.f); SIZE_MAX for future-style / uninitialized.

is_valid()

template<typename S >

bool nros::Client< S >::is_valid ( ) const

inline

Check if the client is initialized and valid.

operator=()

template<typename S >

Client & nros::Client< S >::operator= ( Client< S > &&  other )

inline

send_request()

template<typename S >

Future< ResponseType > nros::Client< S >::send_request ( const RequestType &  req )

inline

Send a request and return a Future for the response (non-blocking).

Call wait() on the returned future to block until the response arrives, or poll with is_ready() / try_take().

Parameters

req	Request to send.

Returns

Future that resolves to the response. Returns a consumed (empty) future on serialization or send failure.

server_available()

template<typename S >

int nros::Client< S >::server_available ( ) const

inline

Phase 124.C.3 — graph-aware "is the matching server up?" probe.

Returns the count from the RMW backend's matched-server view:

• 1 — at least one matching server is currently visible.
• 0 — no matching server discovered yet.
• -1 — backend cannot answer (e.g. XRCE without participant enumeration); caller must fall back to a timed wait_for_service or assume reachability.

Never spins the executor — synchronous, safe to call from inside callbacks. Mirrors rclcpp::ClientBase::service_is_ready but with a tri-state result instead of collapsing "don't know" and "no" into the same false.

Friends And Related Symbol Documentation

Node

template<typename S >

friend class Node

friend

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The documentation for this class was generated from the following files:

• include/nros/node.hpp
• include/nros/client.hpp