On: C2x: the next real revision of the C standard

[Matthias247]

However your implementation based on std::function might allocate, which is then non-zero cost compared to normal exit statements. Better directly store the lambda inside the class, which requires that to be generic (Finally<LambdaType>). That can be hidden by using the class via a templated function which uses types interference:

    auto cleanup_socket = make_scope_guard([&]{ close_socket(s); });

Searching for scope_guard yields lots of alternative implementations.

[frankzinger → Matthias247]

make_* functions are no longer necessary in C++17 which adds "Class template argument deduction" [1]. You can now do

  std::pair p{"aaa", 123};

and

  Finally guard{[]{cleanup();}};

without specifying template arguments.

[1] https://en.cppreference.com/w/cpp/language/class_template_ar...

[Matthias247 → frankzinger]

Thx, I wasn't aware about this feature yet!