are_trait test case (for Stack Overflow question), C++ (vc++)

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#ifndef   ARE_TRAIT_H
    #define   ARE_TRAIT_H
    
    #include <type_traits>
    
    // Based on SameComparison::are_same, by dyp ( http://stackoverflow.com/a/20047561/5386374 )
    
    template<template<typename...> class Trait_t,
             typename... Ts>
    struct are_trait;
    
    // One-parameter trait.
    template<template<typename> class Trait_t,
             typename... Ts>
    struct are_trait<Trait_t, Ts...> : std::true_type {};
    
    template<template<typename> class Trait_t,
             typename T,
             typename... Ts>
    struct are_trait<Trait_t, T, Ts...>
      : std::integral_constant<bool,
                               Trait_t<T>::value &&
                                 are_trait<Trait_t, Ts...>::value> {};
    
    
    // Two-parameter trait, compares all to first element after trait.
    template<template<typename, typename> class Trait_t,
             typename To,
             typename... Froms>
    struct are_trait<Trait_t, To, Froms...> : std::true_type {};
    
    template<template<typename, typename> class Trait_t,
             typename To,
             typename From,
             typename... Froms>
    struct are_trait<Trait_t, To, From, Froms...>
      : std::integral_constant<bool,
                               Trait_t<From, To>::value &&
                                 are_trait<Trait_t, To, Froms...>::value> {};

#endif // ARE_TRAIT_H
    
    int dummy() { return 0; }
    
    int main() {
        // Single-parameter trait:
        static_assert(are_trait<std::is_pointer, int*, void*, decltype(&dummy)>::value,
                      "int*, void*, and decltype(&dummy) aren't all pointers.");
        //static_assert(are_trait<std::is_pointer, int*, void*, int>::value,
        //              "int*, void*, and int aren't all pointers.");

// Two-parameter traits:
        static_assert(are_trait<std::is_same, int, int, int>::value,
                      "int, int, and int aren't all int.");
        //static_assert(are_trait<std::is_same, int, int, decltype(&dummy)>::value,
        //              "int, int, and decltype(&dummy) aren't the same.");
        
        static_assert(are_trait<std::is_convertible, int, char, bool, float, long>::value,
                      "char, bool, float, and long aren't all convertible to int.");
        //static_assert(are_trait<std::is_convertible, int, char, bool, float, decltype(nullptr)>::value,
        //              "char, bool, float, and nullptr_t aren't all convertible to int.");
    }

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Compilation time: 1,13 sec, absolute service time: 1,16 sec