A similar question has been asked before, but I'm still confused. The STL, I believe, exclusively passes by value, as passing by reference might have consequences in a multi-threaded environment. Say, when two or more threads are executing a mutable lambda. I currently use a universal reference when I just want to invoke a lambda:
template <typename F>
inline void invoke(F&& f)
{
f();
}
This binds to any function object, just like a const& would, but maybe it's a bad idea for inlining. Is a lambda passed by copy easier to inline by the compiler? I'd like the passed lambdas to be as "inlinable" as possible.