How to pass a c++ functor rvalue reference to a capture of a lambda ? -

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i have following function

template<class function> void f(function&& g) {     h(..., [&g](){g();}); }

it's function f accepting function, lambda or functor argument. inside calls function h pass lambda argument calling g , receives g capture.

  1. should pass g or &g in capture field of lambda ?
  2. will functor copied above code ?

if capture g reference, is, syntax &g shown in snippet, no copy performed. preferred way. should copy if lambda might called after f finishes, potentially implies destruction of object g refers to.
in case, forwarding cheaper though:

template<class function> void f(function&& g) {     h(…, [g=std::forward<function>(g)] {g();}); }

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