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c++ - Why can't unique_ptr's template arguments be deduced?

When you have class template argument deduction available from C++17, why can't you deduce the template arguments of std::unique_ptr? For example, this gives me an error:

std::unique_ptr smp(new D);

That says "Argument list of class template is missing".

Shouldn't the template arguments (at least the pointer type) be deducable?

See this:

any declaration that specifies initialization of a variable and variable template

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Lets look at new int and new int[10]. Both of those return an int*. There is no way to tell if you should have unique_ptr<int> or unique_ptr<int[]>. That right there is enough not to provide any sort of deduction guide.


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