uninstanciated_template_match.cpp

#include <utility>

template<typename T>
struct sample_templated
{
    T x;
    int y;
};

using instanciated = sample_templated<double>;

template<template<typename...> typename T>
struct types_match_impl
{
    template<typename... ArgTs>
    static std::true_type match(T<ArgTs...>);

    template<typename O>
    static std::false_type match(O);
};

template<template<typename...> typename T, typename O>
struct types_match
{
    constexpr static bool value = decltype(types_match_impl<T>::match(std::declval<O>()))::value;
};

template<template<typename...> typename T, typename O>
constexpr bool types_match_v = types_match<T, O>::value;

int main()
{
    static_assert(types_match_v<sample_templated, instanciated>);
    static_assert(!types_match_v<sample_templated, int>);
}