boost enable_if_c example

Consider the following code adapted from Polukhin's book:

	#include <iostream>
	#include <boost/utility/enable_if.hpp>
	#include <boost/type_traits/is_integral.hpp>
	#include <boost/type_traits/is_float.hpp>
	// Generic implementation
	template <class T, class enable = void>
	class data_processor {
	public:
	double process(const T& v1, const T& v2, const T& v3)
	{
	std::cout << __PRETTY_FUNCTION__ << std::endl;
	}
	};
	// Integral types optimized version
	template <class T>
	class data_processor<T, typename boost::enable_if_c<boost::is_integral<T>::value>::type>
	{
	public:
	double process(const T& v1, const T& v2, const T& v3)
	{
	std::cout << __PRETTY_FUNCTION__ << std::endl;
	}
	};
	// SSE optimized version for float types
	template <class T>
	class data_processor<T, typename boost::enable_if_c<boost::is_float<T>::value>::type>
	{
	public:
	double process(const T& v1, const T& v2, const T& v3)
	{
	std::cout << __PRETTY_FUNCTION__ << std::endl;
	}
	};
	template <class T>
	double example_func(T v1, T v2, T v3) {
	data_processor<T> proc;
	return proc.process(v1, v2, v3);
	}
	int main () {
	// Integral types optimized version will be called
	example_func(1, 2, 3);
	short s = 0;
	example_func(s, s, s);
	// Real types version will be called
	example_func(1.0, 2.0, 3.0);
	example_func(1.0f, 2.0f, 3.0f);
	// Generic version will be called
	example_func("Hello", "word", "processing");
	return 0;
	}

view raw c.cpp hosted with ❤ by GitHub

When run:

kuyu@ub16:~/dkuyu/Dropbox/practice/cpp/boost/polukhin/ch04/enable_if_c$ g++ -I~/dkuyu/bin/boost_1_60_0 c.cpp && ./a.out
double data_processor<T, typename boost::enable_if_c<boost::is_integral<T>::value>::type>::process(const T&, const T&, const T&) [with T = int; typename boost::enable_if_c<boost::is_integral<T>::value>::type = void]
double data_processor<T, typename boost::enable_if_c<boost::is_integral<T>::value>::type>::process(const T&, const T&, const T&) [with T = short int; typename boost::enable_if_c<boost::is_integral<T>::value>::type = void]
double data_processor<T, typename boost::enable_if_c<boost::is_float<T>::value>::type>::process(const T&, const T&, const T&) [with T = double; typename boost::enable_if_c<boost::is_float<T>::value>::type = void]
double data_processor<T, typename boost::enable_if_c<boost::is_float<T>::value>::type>::process(const T&, const T&, const T&) [with T = float; typename boost::enable_if_c<boost::is_float<T>::value>::type = void]
double data_processor<T, enable>::process(const T&, const T&, const T&) [with T = const char*; enable = void]