Question

I have in essence the following code:

typedef std::function<void ()> fnGlobalChangeEvent;
typedef std::vector<fnGlobalChangeEvent> GlobalTriggers;

inline void ExecuteGlobal(fnGlobalChangeEvent ev)
{
    ev();
}

GlobalTriggers triggers;
std::for_each(triggers.begin(), triggers.end(), std::bind(&ExecuteGlobal, _1));

The use of ExecuteGlobal feels totally redundant here, but I can’t find the right syntax to drop out the call.

std::for_each(triggers.begin(), triggers.end(), ExecuteGlobal(_1));
std::for_each(triggers.begin(), triggers.end(), std::bind(_1));

Both fail to compile.

There is also a more complex case:

typedef std::function<void (Zot&)> fnChangeEvent;
typedef std::vector<fnChangeEvent> Triggers;

inline void Execute(fnChangeEvent ev, Zot& zot)
{
    ev(zot);
}

Triggers triggers;
std::for_each(triggers.begin(), triggers.end(), std::bind(&Execute, _1, zot));

Is it possible to do without the helper functions in these cases?

Answer 1

Sure, a lambda:

std::for_each(
    triggers.begin(), triggers.end(),
    [](fnChangeEvent ev) { ev(); }
);
std::for_each(
     triggers.begin(), triggers.end(),
     [&zot](fnChangeEvent ev) { ev(zot); }
);

Or even better, range for:

for (auto ev : triggers) {
    ev();
}

// well, I think you can figure out the second one