For compile time checker which tests whether a type T is std::list I’ve came up with this template:

#include <list>;

template <typename T>
struct is_std_list: std::false_type
{};

template <typename T, typename Allocator>
struct is_std_list<std::list<T, Allocator>>: std::true_type
{};

template <typename T>
inline constexpr bool is_std_list_v = is_std_list<T>::value;

int main()
{
    static_assert(is_std_list_v<std::list<int>>);
    return 0;
}

And my question is: Is it necessary to have #include <list> or having forward declaration of std::list would be enough? (Because actually I also need to write similar templates for std::vector, std::map, std::set and so on. And I’am afraid if having included all those headers can potentially hit compilation time.):

#include <memory>;

namespace std
{
template <class T, class Allocator = allocator<T>>
class list;
}

template <typename T>
struct is_std_list: std::false_type
{};

template <typename T, typename Allocator>
struct is_std_list<std::list<T, Allocator>>: std::true_type
{};

template <typename T>
inline constexpr bool is_std_list_v = is_std_list<T>::value;

int main()
{
    static_assert(is_std_list_v<std::list<int>>);
    return 0;
}