#
Entities in the C++ standard library have
external linkage
.
Unless otherwise specified, objects and functions have the default
extern
"C++"
linkage (
[dcl.
link]
)
.
2
#
Whether a name from the C standard library declared with external linkage has
extern
"C"
or
extern
"C++"
linkage is
implementation-defined
.
It is recommended that an implementation use
extern
"C++"
linkage for this purpose
.
142
3
#
Objects and functions defined in the library and required by a C++ program are included in the program prior to program startup
.
4
#
See also
replacement functions
,
runtime changes
.
142)
142)
The only reliable way to declare an object or function signature from the C standard library is by including the header that declares it, notwithstanding the latitude granted in ISO/IEC 9899:2024, 7.1.4
.