[support.c.headers.general] (original) (raw)

For compatibility with theC standard library, the C++ standard library provides the C headers shown in Table 47.

The intended use of these headers is for interoperability only.

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

[Note 1:

The C headers either have no effect, such as <stdbool.h> and <stdalign.h>, or otherwise the corresponding header of the form <c_name_>provides the same facilities and assuredly defines them in namespace std.

— _end note_]

[Example 1:

The following source file is both valid C++ and valid C. Viewed as C++, it declares a function with C language linkage; viewed as C it simply declares a function (and provides a prototype).

#include <stdbool.h> // for bool in C, no effect in C++ #include <stddef.h> // for size_t #ifdef __cplusplus // see [cpp.predefined] extern "C" // see [dcl.link] #endif void f(bool b[], size_t n); — _end example_]