为什么 std::sort 不要求用户指定模板类型？

Question

If I understand correctly, in the Standard Library, there exists this definition of std::sort() :

template< class RandomIt > 
constexpr void sort( RandomIt first, RandomIt last );

Suppose I have such a vector that I wish to sort:

std::vector<int> data {9, 7, 5, 3, 1};

If this is the case, then why can I just write:

std::sort(data.begin(), data.end());

as opposed to requiring:

std::sort<std::vector<int>::iterator>(data.begin(), data.end());

If possible, could someone provide a generic explanation? I think I've definitely seen more than one instance of this where the template type almost seems to be automatically deduced... or is it being automatically deduced...?

Answer 1

or is it being automatically deduced...?

Yes.

When a template parameter is used for a function parameter, the template argument can be deduced from the argument passed to the function. So, in this case RandomIt is deduced from the arguments data.begin() and data.end() .