C++ keyword: requires (since C++20)
From cppreference.com
C++
Feature test macros (C++20)
Concepts library (C++20)
Metaprogramming library (C++11)
Ranges library (C++20)
Filesystem library (C++17)
Concurrency support library (C++11)
Execution control library (C++26)
C++ language
Flow control Conditional execution statements Iteration statements (loops) Jump statements Functions Function declaration Lambda function expression Dynamic exception specifications (until C++17*) Exceptions Namespaces Types Specifiers Storage duration specifiers Initialization Alternative representations Literals Boolean - Integer - Floating-point Character - String - nullptr (C++11) User-defined (C++11) Utilities Attributes (C++11) Types Type alias declaration (C++11) Casts Memory allocation Classes Class-specific function properties Special member functions Templates Miscellaneous
General topics
inline specifier noexcept specifier (C++11)typedef declaration Keywords
Identifiers with special meaning
(C++11)
(C++11)
(*)
(C++20)
(C++11)
(C++11)
(C++20)
(C++20)
(C++11)
(C++20)
(C++26)
(C++20)
(C++20)
(C++20)
(C++11)
[edit] Usage
- Specifies a constant expression on template parameters that evaluate a requirement.
- Within such a requirement, introduces a nested requirement.
- In a template declaration, specifies an associated constraint.
[edit] Notes
| Feature-test macro | Value | Std | Feature |
|---|---|---|---|
__cpp_concepts |
201907L |
(C++20) | Constraints |