In C++14, you can mark a function as deprecated using the [[deprecated]] attribute (see section 7.6.5 [dcl.attr.deprecated]).
The attribute-token
deprecatedcan be used to mark names and entities whose use is still allowed, but is discouraged for some reason.
For example, the following function foo is deprecated:
[[deprecated]]
void foo(int);
It is possible to provide a message that describes why the name or entity was deprecated:
[[deprecated("Replaced by bar, which has an improved interface")]]
void foo(int);
The message must be a string literal.
For further details, see “Marking as deprecated in C++14”.