dtolnay/cxx

Shared structs with type parameters

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#54 opened on Mar 2, 2020

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help wanted

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Description

We should support structs that have type parameters and translate them to an ABI-compatible class template in C++.

#[cxx::bridge]
mod ffi {
    struct Generic<T> {
        wow: T,
    }

    extern "C" {
        fn f(g: Generic<String>);
    }
}

Contributor guide

Research direction
Study the existing code that handles non generic structs in the cxx bridge and extend it to support type parameters. Look into how C++ class templates can be generated from Rust generic types. Check the code generation logic and the representation of types.
Tech stack
rustc
Domain
api
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.
1-2 days
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