Does MSVC support C++11-style attributes instead of __declspec?

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I know that C++11-style attributes support vendor-specific attributes that are prefixed by a namespace. Both GCC and Clang support various attributes with the prefix either gnu:: (gcc and clang) or clang:: (clang only) which correspond to an equivalent __attribute__((...)) syntax.

The documentation for MSVC attributes shows that it supports the standard attributes, as well as a gsl:: attribute -- but it makes no mention of backwards-compatibility for __declspec attributes.

I'd expect something like __declspec(noinline) to have an attribute representation of [[msvc::noinline]] -- but I can't seem to find any documentation on this.

So my question is, does MSVC support __declspec as C++11-style attributes at all?

If it doesn't, would anyone happen to know they don't? The original rationale for C++'s attributes was to abstract the various compiler-specific __attribute__ and __declspec features, so it would be weird if it's still not supported 9 years after standardization.

visual-c++ c++
2 Answers

There is no [[msvc::noinline]] or other __declspec equivalents as of VC++ 2019.

From the official MSVC documentation for Attributes in C++:

In Visual C++, you can use the [[deprecated]] attribute instead of using declspec(deprecated) and the attribute will be recognized by any conforming compiler. For all other declspec parameters such as dllimport and dllexport, there is as yet no attribute equivalent so you must continue to use declspec syntax.

[ EDIT ]   Information on why [[attributes]] are not more widely used in VC++, perhaps replacing __declspec entirely, is surprisingly scarce. The closest to an authoritative source that I found were these comments in the reddit thread C++ attribute specifier sequence, MSVC and me:

spongo2 - MSVC Dev Manager

We just had a rousing team room discussion on this topic. We definitely see the use case here and it's interesting but we're wondering if the fact that the number of places one can put attributes is large and growing would lead to surprising behavior.

STL - MSVC STL Dev

I would use [[msvc::kitty]] instead of __declspec(kitty) in the STL, in order to make our sources more palatable to other front-ends. I already switched to using [[noreturn]] instead of __declspec(noreturn) because that one's Standard.

My reading is that what's holding back a wider adoption is the concern about scopes of attributes vs. __declspec, and backwards compatibility in general.

user_55384200

According to Attributes in C++ the only __declspec() with an attribute replacement is [[deprecated]], for all other __declspec() modifiers you must continue to use __declspec.

user_75947110
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