Where can I find information on the C++ [[deprecated]] attribute

Question

I got sent a link describing a [[deprecated]] attribute in C++11. This sound pretty convenient, and I would like to have more information about it - which compilers support it, full documentation on it, etc.

I spent 20 minutes or so googling around, but apart from the linked website, I couldn't find infos on this anywhere. Partly, this was complicated by other uses of the word "deprecated" in connection with C++11, and search engines not recognizing [[. I didn't find this in draft standards linked to in various SO answers, either. I don't have access to the full, paid, standard.

Does anybody have more information about this [[deprecated]] attribute?

P.S.: If you're curious, I'd use this as a better alternative to https://stackoverflow.com/a/295229/599884

Answer 1

The [[deprecated]] attribute has made its way into the draft of C++14 (see section 7.6.5 [dcl.attr.deprecated] of the October 2013 draft).

The attribute-token deprecated can 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.

Answer 2

First, things in [[]] are not keywords; they are attributes.

Second, there is no [[deprecated]] attribute defined by the C++11 standard. The link you're referring to is either in error or referring to a specific compiler (C++Builder, perhaps?) that implements this attribute.

Attributes are (usually) compiler specific. Like #pragmas, compilers are supposed to ignore any attribute they don't support.