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// 2.15.variadic.template.param.cpp

// chapter 2 language usability

// modern cpp tutorial

// created by changkun at changkun.de

// https://github.com/changkun/modern-cpp-tutorial

#include <iostream>

#include <vector>

#include <string>

// sizeof...

template<typename... Ts>

void magic(Ts... args) {

std::cout << sizeof...(args) << std::endl;

}

// 1. recursive parameter unpack

template<typename T0>

void printf1(T0 value) {

std::cout << value << std::endl;

}

template<typename T, typename... Ts>

void printf1(T value, Ts... args) {

std::cout << value << std::endl;

printf1(args...);

}

// 2. variadic template parameter unfold

template<typename T0, typename... T>

void printf2(T0 t0, T... t) {

std::cout << t0 << std::endl;

if constexpr (sizeof...(t) > 0) printf2(t...);

}

// 3. parameter unpack using initializer_list

template<typename T, typename... Ts>

auto printf3(T value, Ts... args) {

std::cout << value << std::endl;

(void) std::initializer_list<T>{([&args] {

std::cout << args << std::endl;

}(), value)...};

}

int main() {

magic();

magic(1);

magic(1,"");

printf1(1, 2, "123", 1.1);

printf2(1, 2.3, "abc");

printf3(111, 123, "alpha", 1.2);

return 0;

}

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