{{#title std::vector<T> — Rust ♡ C++}}

std::vector<T>

The Rust binding of std::vector<T> is called CxxVector<T>. See the link for documentation of the Rust API.

Restrictions:

Rust code can never obtain a CxxVector by value. Instead in Rust code we will only ever look at a vector behind a reference or smart pointer, as in &CxxVector<T> or UniquePtr<CxxVector<T>>.

CxxVector<T> does not support T being an opaque Rust type. You should use a Vec<T> (C++ rust::Vec<T>) instead for collections of opaque Rust types on the language boundary.

Example

This program involves Rust code converting a CxxVector<CxxString> (i.e. std::vector<std::string>) into a Rust Vec<String>.

// src/main.rs

#![no_main] // main defined in C++ by main.cc

use cxx::{CxxString, CxxVector};

#[cxx::bridge]
mod ffi {
    extern "Rust" {
        fn f(vec: &CxxVector<CxxString>);
    }
}

fn f(vec: &CxxVector<CxxString>) {
    let vec: Vec<String> = vec
        .iter()
        .map(|s| s.to_string_lossy().into_owned())
        .collect();
    g(&vec);
}

fn g(vec: &[String]) {
    println!("{:?}", vec);
}

// src/main.cc

#include "example/src/main.rs.h"
#include <string>
#include <vector>

int main() {
  std::vector<std::string> vec{"fearless", "concurrency"};
  f(vec);
}