book: improve NULL example (#133)

This commit is contained in:
sunshaoce
2020-10-03 15:27:14 +08:00
committed by GitHub
parent 212f4f3503
commit c9f8eb70fd
3 changed files with 123 additions and 120 deletions

View File

@@ -53,7 +53,8 @@ void foo(char *);
void foo(int);
int main() {
if (std::is_same<decltype(NULL), decltype(0)>::value)
if (std::is_same<decltype(NULL), decltype(0)>::value ||
std::is_same<decltype(NULL), decltype(0L)>::value)
std::cout << "NULL == 0" << std::endl;
if (std::is_same<decltype(NULL), decltype((void*)0)>::value)
std::cout << "NULL == (void *)0" << std::endl;

View File

@@ -43,7 +43,8 @@ void foo(char *);
void foo(int);
int main() {
if (std::is_same<decltype(NULL), decltype(0)>::value)
if (std::is_same<decltype(NULL), decltype(0)>::value ||
std::is_same<decltype(NULL), decltype(0L)>::value)
std::cout << "NULL == 0" << std::endl;
if (std::is_same<decltype(NULL), decltype((void*)0)>::value)
std::cout << "NULL == (void *)0" << std::endl;

View File

@@ -14,7 +14,8 @@ void foo(char *);
void foo(int);
int main() {
if (std::is_same<decltype(NULL), decltype(0)>::value)
if (std::is_same<decltype(NULL), decltype(0)>::value ||
std::is_same<decltype(NULL), decltype(0L)>::value)
std::cout << "NULL == 0" << std::endl;
if (std::is_same<decltype(NULL), decltype((void*)0)>::value)
std::cout << "NULL == (void *)0" << std::endl;