Trait SecNanosecMsg 

pub trait SecNanosecMsg: Sized {
    // Required method
    fn from_sec_nanosec(sec: i32, nanosec: u32) -> Self;
}

A generated message whose field set is { sec: i32, nanosec: u32 } — builtin_interfaces/msg/Time and its Duration twin.

This is the Rust substitute for a C++ template parameter. nros-cpp spells the same conversion as template <typename TimeMsgT> void Time::to_msg(TimeMsgT&) (packages/api/nros-cpp/include/rclcpp/time.hpp), which binds structurally to anything carrying sec / nanosec. Rust has no structural bound, so the same trick needs an AUTHORED trait that rosidl-codegen implements for every generated message with that exact field set — the same binding set the C++ template has, decided by SHAPE rather than by a hard-coded package name.

Why the trait lives here and the impl does not: nros-core can never name a message type. Every generated message crate depends on nros-core, so a dependency the other way is a cycle, and message types are generated per USER package (RFC-0023 / RFC-0067) — there is no one crate for the client library to name. The trait is the seam that lets the conversion cross that edge without an edge.

Implemented by codegen; nothing in this crate implements it.

Required Methods

fn from_sec_nanosec(sec: i32, nanosec: u32) -> Self

Build the message from an already-decomposed timestamp.

Infallible by construction — both components are already the message’s own field types. See Time::to_ros_msg for why no Result appears here.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors