[lucic71]

- template <typename T1> std::unique_ptr<T1[]> f1(std::size_t n) {
-  return std::make_unique<T1[]>(n);
+ template <typename T1> auto f1(std::size_t a0) {
+  return std::make_unique<T1>(a0);
}

There is no std::make_unique<T1[]>(n) in the standard, only std::make_unique<T1>(a0). Spell the rules as the standard does.

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For that, I added a new marker trait called CppArray that unwraps the element so that the rule for array make_unique can be written as:

unsafe fn f1<T1: CppArray<T2>, T2: Default>(a0: usize) -> Option<Box<[T2]>> {
    Some((0..a0).map(|_| <T2>::default()).collect::<Box<[_]>>())
}

CppArray uses the same infrastructure as CppFrom and CppIterator.

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I also had to add a fallback for matching the template arguments. In the new spelling of make_unique, T1 becomes undeducible because it does not appear in the arguments or returns type of the rule. So we deduce T1 from the callee of the return expr.