nros::Expected< T > Class Template Reference

#include <result.hpp>

Public Member Functions
ErrorCode	error () const
Result	error_as_result () const
bool	ok () const
	operator bool () const
T &	value () &
T &&	value () &&
const T &	value () const &

Static Public Member Functions
static Expected	error (const Result &r)
static Expected	error (ErrorCode code)
static Expected	ok (T value)

Detailed Description

template<typename T>
class nros::Expected< T >

Phase 123.B.4 — templated value-or-error wrapper.

Lets factory functions return constructed entities by value instead of forcing the out-param + Result idiom. Trade-off: requires T to be default-constructible and move-constructible (Node, Publisher, Subscription all satisfy both today). Storage is direct (the value lives inline, no allocation) — when the result holds an error the value member is default-constructed and idle.

Usage:

auto node_r = nros::Node::make("my_node");
if (!node_r.ok()) return node_r.error_as_result();
auto& node = node_r.value();

Out-param create_node(node, "name") remains the canonical zero-cost API for embedded / strictly-no-alloc code; make() is a hosted-friendly convenience that closes the rclcpp / rclrs idiom gap.

Member Function Documentation

error() [1/3]

template<typename T >

ErrorCode nros::Expected< T >::error ( ) const

inline

error() [2/3]

template<typename T >

static Expected nros::Expected< T >::error ( const Result &  r )

inlinestatic

error() [3/3]

template<typename T >

static Expected nros::Expected< T >::error ( ErrorCode  code )

inlinestatic

error_as_result()

template<typename T >

Result nros::Expected< T >::error_as_result ( ) const

inline

ok() [1/2]

template<typename T >

bool nros::Expected< T >::ok ( ) const

inline

ok() [2/2]

template<typename T >

static Expected nros::Expected< T >::ok ( T  value )

inlinestatic

operator bool()

template<typename T >

nros::Expected< T >::operator bool ( ) const

inlineexplicit

value() [1/3]

template<typename T >

T & nros::Expected< T >::value ( ) &

inline

value() [2/3]

template<typename T >

T && nros::Expected< T >::value ( ) &&

inline

value() [3/3]

template<typename T >

const T & nros::Expected< T >::value ( ) const &

inline

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

• include/nros/result.hpp