Overview
ISO/IEC TS 19216:2018 - Programming Languages - C++ Extensions for Networking specifies a set of extensions to the C++ Standard Library to support networking operations. Published as a Technical Specification in 2018, it defines requirements for implementations of a C++ networking interface covering sockets, timers, buffer management, host name resolution and internet protocols. The specification targets vendors implementing the interface on systems that can perform network operations (for example, POSIX-conforming operating systems).
Key topics and technical requirements
- Asynchronous model & executors: Defines an asynchronous programming model including executor types, work guards, and async_result/async_completion utilities to support non-blocking I/O and task dispatch.
- I/O services (io_context): Specifies the core I/O context/execution environment used to run asynchronous operations and manage event loops.
- Timers: Standardizes waitable timer types and related semantics for synchronous and asynchronous time-based operations.
- Buffers and buffer management: Describes mutable/const buffer types, buffer sequences, dynamic buffer helpers, and utility functions (buffer_size, buffer_copy) for efficient data handling.
- Sockets and socket algorithms: Defines socket base classes, stream and datagram socket templates, acceptors, socket options, and synchronous/asynchronous connect/read/write algorithms.
- Internet protocol utilities: Specifies IP address and endpoint classes, resolver interfaces for host name resolution, and protocol-specific types (tcp/udp).
- Error reporting & conformance: Covers synchronous vs asynchronous error handling, POSIX-referenced behavior, and documentation requirements for deviations from POSIX.
- Library layout & headers: Introduces convenience and experimental headers such as , , , , and .
Practical applications and who uses it
- Library vendors and implementers: Primary audience - C++ library maintainers, runtime vendors and OS integrators who implement the standardized networking API.
- Framework and middleware developers: Build portable networking frameworks, high-performance servers, and cross-platform communication libraries leveraging the standardized async model, io_context and buffers.
- Application developers: Benefit indirectly - consistent, portable C++ networking APIs make it easier to write robust socket, timer, and resolver code across platforms.
- Embedded and IoT systems: Implementations on POSIX-like or constrained OSs enable standardized network I/O for device software.
Related standards
- ISO/IEC 14882:2014 - C++ (the C++ Standard referenced by this TS)
- ISO/IEC 9945:2009 (POSIX) - Operating system interface referenced for behavior alignment
- ISO/IEC TS 19568:2015 - C++ Extensions for Library Fundamentals
This Technical Specification is useful for anyone researching "C++ networking", "sockets in C++", "async I/O C++", "io_context", "C++ buffer management", and "POSIX C++ networking implementations".