只处理存放类型的模板

附：对于编译器而言，using 重命名模板和原模板在实例化以前属于两个模板，不能简单使用std::is_same的逻辑来处理两个模板是否相同的问题。

#ifndef TEMPLATE_PROCESSING_H
#define TEMPLATE_PROCESSING_H#include <cstddef>
#include <type_traits>template <typename Type, template <typename ...> class Template>
struct is_instance_of
{
private:template<typename ...CheckType>static void check (Template<CheckType...>);template<typename ...CheckType>static bool check (...);
public:static constexpr bool value = std::is_void<decltype (check (std::declval<Type>())) >::value;
};template<size_t i>
struct template_filler
{template<template<typename...>class Template, typename ...Args>using apply = typename template_filler < i - 1 >::template apply<Template, Args..., void>;
};template<>
struct template_filler<0>
{template<template<typename...>class Template, typename ...Args>using apply = Template<Args...>;
};template<template<typename...>class Template, size_t i = 0, typename = void>
struct template_mix_size
{static constexpr size_t value = template_mix_size < Template, i + 1 >::value;using type = typename template_mix_size < Template, i + 1 >::type;
};template<template<typename...>class Template, size_t i>
struct template_mix_size<Template, i, std::void_t<typename template_filler<i>::template apply<Template>>>
{static constexpr size_t value = i;using type = typename template_filler<i>::template apply<Template>;
};template<template<typename...>class TemplateFirst, template<typename...>class TemplateSecond>
struct is_same_template
{
private:template<template<typename...>class TemplateCheck>static void check (typename template_mix_size<TemplateCheck>::type*);template<template<typename...>class TemplateCheck>static bool check (...);
public:static constexpr bool value = std::is_void <decltype (check<TemplateFirst> ( (typename template_mix_size<TemplateSecond>::type*) nullptr))>::value;
};#endif