C11 (C standard revision) features

C11 revision

Table of Contents

• 1. Overview
• 2. Multiple threading
• 3. Generic selection
• 4. Alignment facilities
• 5. Static assertions
• 6. Anonymous structs and unions
• 7. Other features
  • 7.1. quick_exit() function
  • 7.2. _Noreturn function specifier
  • 7.3. Bounds-checking functions
  • 7.4. Unicode support
  • 7.5. complex types
• 8. C17 / C18
• 9. C2x
• 10. References

1 Overview

C11 is the informal name for ISO/IEC 9899:2011, the current standard for the C language that was ratified by ISO in December 2011.

It standardizes many features for safer programming, such as removal of gets() function.

Additionally, C11 adds concurrency support, type-generic expressions, alignment-related facilities, static assertion, unicode support, floating-point characteristic macros, no-return functions, anonymous structures and unions, and various bound-checking and reentrancy functions.

The following examples demonstrating C11 features can be compiled with options such as

clang -std=c11 ex.c

2 Multiple threading

C11 standardized multi-threading support.

It introduces new headers threads.h and stdatomic.h, supporting multiple threads of execution:

• threads creation and management
• mutexes
• conditional variables
• atomic objects
• thread specific storage