Implementing a function that accepts only the user defined types in using the template specialization of C++.

A foo() in below source code will be accepted only the two types like myString and String2, but other types will occur an errors on compile time.

	#include <iostream>
	#include <type_traits>
	struct myString {
	};
	struct ccString1 : public myString {
	};
	struct ccString2 : public myString {
	};
	template<typename T>
	struct check_type
	: std::false_type
	{ // determine whether T is type that we want
	};
	template<>
	struct check_type<myString>
	: std::true_type
	{ // determine whether T is type that we want
	};
	template<>
	struct check_type<ccString2>
	: std::true_type
	{ // determine whether T is type that we want
	};
	template <bool, class T = void>
	struct enable_if
	{};
	template <class T>
	struct enable_if<true, T>
	{
	typedef T type;
	};
	template <class T>
	typename enable_if<check_type<T>::value, T>::type
	foo(T t)
	{
	// …
	return t;
	}
	int main()
	{
	ccString1 str1;
	ccString2 str2;
	foo<ccString1>(str1);
	foo<ccString2>(str2);
	return 0;
	}

view raw restrict_types_using_the_template_specialization.cpp hosted with ❤ by GitHub