modernize-use-nullptr

The check converts the usage of null pointer constants (e.g. NULL, 0) to use the new C++11 and C23 nullptr keyword.

It also replaces references to decltype(nullptr) with std::nullptr_t from <cstdef>.

Example

void assignment() {
  char *a = NULL;
  char *b = 0;
  char c = 0;
}

int *ret_ptr() {
  return 0;
}

void expect_null(decltype(nullptr));

transforms to:

#include <cstddef>

void assignment() {
  char *a = nullptr;
  char *b = nullptr;
  char c = 0;
}

int *ret_ptr() {
  return nullptr;
}

void expect_null(std::nullptr_t);

Options

IgnoredTypes

Semicolon-separated list of regular expressions to match pointer types for which implicit casts will be ignored. Default value: std::_CmpUnspecifiedParam::;^std::__cmp_cat::__unspec.

NullMacros

Comma-separated list of macro names that will be transformed along with NULL. By default this check will only replace the NULL macro and will skip any similar user-defined macros.

UseNullptrT

Boolean controlling whether we should replace decltype(nullptr) with the type std::nullptr_t from <cstddef>. Defaults to true.

IncludeStyle

A string specifying which include-style is used, llvm or google. Default is llvm.

Example

#define MY_NULL (void*)0
void assignment() {
  void *p = MY_NULL;
}

transforms to:

#define MY_NULL NULL
void assignment() {
  int *p = nullptr;
}

if the NullMacros option is set to MY_NULL.