dtolnay/cxx

Improvements to namespace support

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#353 opened on Oct 10, 2020

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help wanted

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Description

This issue is just to track the implementation plan laid out at the bottom of https://github.com/dtolnay/cxx/pull/298#issuecomment-703817493.

  • Emit all mentions of a type in generated C++ code (in function arguments and so forth) as a fully qualified path ::name::space::of::Type, even if it currently always happens to be within the same module. #370

  • Store a distinct Namespace on each FFI item rather than having a single global namespace for the whole code generation. #370

  • Implement #[namespace = ...] attribute to determine namespace of individual items. #370 #380

  • Implement hierarchical handling of namespace which prioritizes item-level attribute > extern block > module. #444

  • Emit ExternType impls for shared structs. #341

  • Safe ExternType derive for extern Rust items. extern "Rust" { #[derive(ExternType)] type TheType; } 16e2620fe51032d789770b489e27a9c6c27719ef

  • Permit use inside of cxx::bridge.

Contributor guide

Research direction
Study the existing namespace support in the cxx code generator, especially how items are resolved across namespaces. Then modify the parser and code generation to allow `use` statements inside `#[cxx::bridge]` blocks.
Tech stack
rustcpp
Domain
tooling
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
RustC++
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60