modern-cpp-tutorial/code/2/2.01.nullptr.cpp at master · baixiangcpp/modern-cpp-tutorial

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// 2.1.nullptr.cpp

// chapter 2 language usability

// modern cpp tutorial

// created by changkun at changkun.de

#include <iostream>

#include <type_traits>

void foo(char *);

void foo(int);

int main() {

if (std::is_same<decltype(NULL), decltype(0)>::value)

std::cout << "NULL == 0" << std::endl;

if (std::is_same<decltype(NULL), decltype((void*)0)>::value)

std::cout << "NULL == (void *)0" << std::endl;

if (std::is_same<decltype(NULL), std::nullptr_t>::value)

std::cout << "NULL == nullptr" << std::endl;

foo(0); // will call foo(int)

// foo(NULL); // doen't compile

foo(nullptr); // will call foo(char*)

return 0;

}

void foo(char *) {

std::cout << "foo(char*) is called" << std::endl;

}

void foo(int i) {

std::cout << "foo(int) is called" << std::endl;

}