matrix-rust-sdk

// Copyright 2025 The Matrix.org Foundation C.I.C.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

//! Platform-specific stream utilities.

//!

//! This module provides a unified `BoxStream` + `StreamExt` class for working

//! with boxed streams across different platforms. On native platforms,

//! streams can be `Send`, but on Wasm they cannot. This module abstracts

//! over that difference.

#[cfg(not(target_family = "wasm"))]

mod sys {

    // On native platforms, just re-export everything from futures_util

    pub use futures_util::{StreamExt, stream::BoxStream};

}

#[cfg(target_family = "wasm")]

mod sys {

    use futures_core::Stream;

    // On Wasm, BoxStream is LocalBoxStream

    pub use futures_util::stream::LocalBoxStream as BoxStream;

    /// Custom `StreamExt` trait for Wasm that provides essential methods

    /// like `.boxed()` and `.next()` without `Send` requirements.

    pub trait StreamExt: Stream {

        /// Box this stream using `LocalBoxStream` (no `Send` requirement).

        fn boxed<'a>(self) -> BoxStream<'a, Self::Item>

        where

            Self: Sized + 'a,

        {

            futures_util::StreamExt::boxed_local(self)

        }

        /// Get the next item from this stream.

        fn next(&mut self) -> futures_util::stream::Next<'_, Self>

        where

            Self: Unpin,

        {

            futures_util::StreamExt::next(self)

        }

    }

    impl<S: Stream> StreamExt for S {}

}

pub use sys::*;