Way for class template to deduce type when constructing an instance with std::make_unique?

user_13699024 0
Viewed 128

Let's say we have a class template Foo, that has one type template parameter that it can deduce from an argument in its constructor. If we use std::make_unique to construct an instance of Foo, is there a way for Foo's constructor to deduce the template arguments as it would have if its constructor was called normally? Is this the simplest way to achieve this?

std::make_unique< decltype(Foo{...}) > (...);

This seems pretty clean but if Foo's constructor takes a lot of arguments it can turn into a pretty ugly line.

template-argument-deduction decltype templates c++
1 Answers

You can leverage a helper function to wrap the ugly code into a pretty wrapper. That would look like

template <typename... Args>
auto make_foo_ptr(Args&&... args)
{
    return std::make_unique<decltype(Foo{std::forward<Args>(args)...})>(std::forward<Args>(args)...);
}
user_43424980
Related