C++26, the upcoming version of the C++ standard, is expected to introduce several key features that will enhance the language's safety, usability, and performance. Here are some of the major features anticipated in C++26:

Key Features of C++26

1. Contracts

• Purpose: Implement design by contract, allowing functions to specify preconditions, postconditions, and invariants.

• Impact: Enhances code reliability by explicitly defining API contracts, reducing runtime errors.

• Example:

   

  cpp

  int f(const int x) [[pre: x != 1]] // precondition [[post(r : r != 2)]] // postcondition { contract_assert(x != 3); return x; }

2. Reflection

• Purpose: Introduce static reflection capabilities, enabling compile-time introspection of types and behavior.

• Impact: Facilitates more powerful metaprogramming and generic programming.

• Status: Initial version approved for C++26, with plans for further expansion in future standards.

3. std::execution (Senders/Receivers)

• Purpose: Provide a standardized framework for managing asynchronous execution on generic execution resources.

• Impact: Simplifies concurrent programming by offering a unified interface for executors.

• Status: Still under development and not yet fully implemented by compilers.

4. Dense Linear Algebra (BLAS)

• Purpose: Integrate Basic Linear Algebra Subprograms (BLAS) into the C++ Standard Library.

• Impact: Enhances numerical computing capabilities with standardized linear algebra operations.

5. SIMD Parallelism

• Purpose: Standardize Single Instruction, Multiple Data (SIMD) operations for parallel processing.

• Impact: Improves performance in data-parallel computations.

6. Safety Proposals

• Purpose: Include safety features such as bounds-checked iterators and null pointer validation in the standard library.

• Impact: Reduces memory safety vulnerabilities by enforcing stricter checks in debug builds.

7. #embed Directive

• Purpose: Allow native inclusion of binary resources directly into C++ code.

• Impact: Simplifies resource management by eliminating the need for external build system hacks.

8. Template Improvements

• Purpose: Enhance template metaprogramming with features like pack indexing.

• Impact: Increases expressiveness and efficiency in generic programming.

9. Structure Bindings in Control Statements

• Purpose: Enable structure bindings in the condition of if, while, or for statements.

• Impact: Improves readability and flexibility in control flow logic.

These features are part of the ongoing development process, with some already approved and others still under refinement. The final set of features will be confirmed as C++26 nears completion.