Answers to theory questions 190111

a) Placement new is a special version of the new-operator that
initializes an object on a specified memory location. It does not
allocate any memory: it only calls the constructor on a specific
memory location. Example:

int x{};
new (&x) int{5};

b) due to the most vexing parse, f will be a function and since cout
does not have an overload for function pointers the compiler will
convert the function-pointer to bool.

c) Example #1:

template <typename T>
void foo(T&& ref) // here T&& is forwarding reference
{

}

Example #2:

auto&& f{ /* ... */ }; // here auto&& is forwarding reference

d) The as if rule states that the compiler is allowed to make any
modifications to the program as long as the observable behaviour is
the same.

e) An inline namespace is a namespace that will export all members into the namespace above.
Example:

inline namespace my_namespace {
  // ...
}

is equivalent to:

namespace my_namespace {
  // ...
}
using namespace my_namespace;