Exception safety and make_unique

Question

Just to clarify, using make_unique only adds exception safety when you have multiple allocations in an expression, not just one, correct? For example

Answer 1

I'd think you'd be better off comparing things actually using std::unique_ptr:

void f(std::unique_ptr);

f(std::unique_ptr(new T));
f(std::make_unique());

Neither of these calls can leak if there is an exception being thrown. However

void f(std::unique_ptr, std::unique_ptr);

g(std::unique_ptr(new T), std::unique_ptr(new T));
g(std::make_unique(), std::make_unique());

In this case, the version using std::unique_ptr explicitly can leak if an exception is thrown (because the compiler might start evaluating the new-expressions before constructing either of the temporaries).