https://DevOpsCloud.io -- Cloud Monk Losang Jinpa, Ph.D., MCSE/MCT, GitOps DevOps Engineer

https://en.cppreference.com/w/cpp/header

The interface of C++ standard library is defined by the following collection of headers.

For some of the C standard library headers of the form

, the C++ standard library both includes an identically-named header and another header of the form

(all meaningful

headers are listed above). The intended use of headers of form

is for interoperability only. It is possible that C++ source files need to include one of these headers in order to be valid ISO C. Source files that are not intended to also be valid ISO C should not use any of the C headers.

With the exception of

<!–LWG 551/2536–>, each

header included in the C++ standard library places in the global namespace each name that the corresponding

header would have placed in the

namespace.

These headers are allowed to also declare the same names in the

namespace, and the corresponding

headers are allowed to also declare the same names in the global namespace: including

definitely provides

and may also provide

. Including

definitely provides

and may also provide

. This applies even to functions and function overloads that are not part of C standard library.

Notes:

headers are deprecated in C++98 and undeprecated in C++23. These headers are discouraged for pure C++ code, but not subject to future removal.

The header

declares names which are also provided in the C standard library, and defines the

macro which is a c/keyword/_Atomic | keyword in C. Unlike other

headers, corresponding

is not provided.

The headers

,

,

, and

do not contain any content from the C standard library and instead merely include other headers from the C++ standard library.

The headers

,

, and

are meaningless in C++ because the macros they provide in C are language keywords in C++.

The C headers

,}}

, and

are not included in C++ and have no

equivalents.

cpp/experimental | C++ TR's/TS's also define several collections of headers.