On 3/22/23 12:38, Dominique Devienne wrote:

On Wed, Mar 22, 2023 at 10:04 AM Andrey Semashev via Boost mailto:boost@lists.boost.org> wrote:

  error_code ec;   scope_fail guard(     [&] { std::cout << "Failure" << std::endl; },     [&ec] { return !!ec; });

Having made the dumb mistake of writing once or twice `scope_fail(...);` instead of `scope_fail guard(...);`, is there a way to prevent that?

One way would be to use BOOST_SCOPE_FINAL. :)

Like [[nodiscard]] with an alternate form like `auto guard = scope_fail(...);` ? I guess that requires move'ability, which might not be desirable?

`auto guard = scope_fail(...);` would work, as scope_fail is moveable. With C++17, I think, you are even guaranteed to elide the move constructor. [[nodiscard]] is not usable here as there's nothing to apply it to, as we're talking about the scope guard constructor.