Use nullptr in code blocks #208

sdutoit · 2013-10-03T16:12:09Z

Use nullptr where we currently use 0 or NULL.

sdutoit · 2013-10-03T16:12:46Z

Related to #52, which is about null values in normative text.

sdutoit · 2013-10-03T17:27:12Z

From a PDF sent to LWG by Geoff Alexander:

C++11 changes to use nullptr rather than 0
Location
From Text
To Text
section 8.3.2, paragraph 3, page 188
p = 0;
p = nullptr;
section 8.3.2, paragraph 3, page 188
q with the value zero
q with the value nullptr
section 9.7, paragraph 1, page 230
inner* p = 0;
inner* p = nullptr;
section 9.8, paragraph 1, page 231
local* p = 0;
local* p = nullptr;
section 14.5.6.2, paragraph 5, page 350
A<U, T>* p = 0
A<U, T>* p = nullptr
section 14.5.6.2, paragraph 5, page 350
A<U, U>* p = 0
A<U, U>* p = nullptr
section 14.7.3, paragraph 13, page 373
char* p = 0;
char* p = nullptr;
section 17.6.5.4, paragraph 4, page 450
delim != 0
delim != nullptr
section 29.6.9, page 535
hint = 0
hint = nullptr
section 29.6.9.1, paragraph 4, page 536
hint = 0
hint = nullptr
section 21.3, page 637 (multiple occurrences)
size_t idx = 0
size_t *idx = nullptr
section 21.5, pages 665-666 (multiple occurrences)
size_t *idx = 0
size_t *idx = nullptr
section 21.5, pages 665-666 (multiple occurrences)
idx != 0
idx != nullptr
section 21.3.3.2.3, paragraph 2, page 683
std::streambuf *bytebuf = 0
std::streambuf *bytebuf = nullptr
section 21.3.3.2.3, paragraph 9, page 684
std::streambuf *bytebuf = 0
std::streambuf *bytebuf = nullptr
section 22.4.1.3, page 688
const mask tab = 0
const mask* tab = nullptr
section 22.4.1.3.2, paragraph 2, page 689
const mask* tbl = 0
const mask* tbl = nullptr
section 22.4.1.3.2, paragraph 2, page 690
tbl either 0
tbl either nullptr
section 24.6.1.1, paragraph 2, page 856
in_stream == 0
in_stream == nullptr
section 24.6.1.2, paragraph 3, page 857
in_stream != 0
in_stream != nullptr
section 24.6.1.2, paragraph 6, page 857
in_stream != 0
in_stream != nullptr
section 24.6.2.2, paragraph 1, page 858
delim != 0
delim != nullptr
section 27.5.5.3, paragraph 9, page 1007
rdbuf() != 0
rdbuf() != nullptr
section 27.5.5.4, paragraph 4, page 1009
rdbuf() != 0
rdbuf() != nullptr
section 27.5.5.4, paragraph 5, page 1009
rdbuf()
rdbuf() != nullptr
section D.7.1, page 1231-1232 (multiple occurrences)
char* pbeg_arg = 0
char* pbeg_arg = nullptr
section D.7.1.1, page 1233 (multiple occurrences)
char* pbeg_arg = 0
char* pbeg_arg = nullptr
section D.10.1, page 1245 (multiple occurrences)
X* p =0
X* p = nullptr
section D.10.1.1, page 1246
X* p =0
X* p = nullptr
section D.10.1.2, page 1247
get() != 0
get() != nullptr
section D.10.1.2, page 1247
X* p =0
X* p = nullptr

Eelis · 2016-07-30T17:14:00Z

Here's the result of egrep "\* *[a-zA-Z_]* *= *0" *.tex (perhaps easier to read than the list above):

classes.tex:597:  T * p = 0;        // OK: \grammarterm{brace-or-equal-initializer}
classes.tex:1434:inner* p = 0;                   // error: \tcode{inner} not in scope
classes.tex:1798:local* p = 0;                   // error: \tcode{local} not in scope
future.tex:154:    strstreambuf(char* gnext_arg, streamsize n, char* pbeg_arg = 0);
future.tex:158:                 signed char* pbeg_arg = 0);
future.tex:161:                 unsigned char* pbeg_arg = 0);
future.tex:311:strstreambuf(char* gnext_arg, streamsize n, char* pbeg_arg = 0);
future.tex:313:             signed char* pbeg_arg = 0);
future.tex:315:             unsigned char* pbeg_arg = 0);
locales.tex:1323:    explicit wbuffer_convert(std::streambuf* bytebuf = 0,
locales.tex:1409:explicit wbuffer_convert(std::streambuf* bytebuf = 0,
locales.tex:1954:    explicit ctype(const mask* tab = 0, bool del = false,
locales.tex:2048:explicit ctype(const mask* tbl = 0, bool del = false,
strings.tex:754:  int stoi(const string& str, size_t* idx = 0, int base = 10);
strings.tex:755:  long stol(const string& str, size_t* idx = 0, int base = 10);
strings.tex:756:  unsigned long stoul(const string& str, size_t* idx = 0, int base = 10);
strings.tex:757:  long long stoll(const string& str, size_t* idx = 0, int base = 10);
strings.tex:758:  unsigned long long stoull(const string& str, size_t* idx = 0, int base = 10);
strings.tex:759:  float stof(const string& str, size_t* idx = 0);
strings.tex:760:  double stod(const string& str, size_t* idx = 0);
strings.tex:761:  long double stold(const string& str, size_t* idx = 0);
strings.tex:772:  int stoi(const wstring& str, size_t* idx = 0, int base = 10);
strings.tex:773:  long stol(const wstring& str, size_t* idx = 0, int base = 10);
strings.tex:774:  unsigned long stoul(const wstring& str, size_t* idx = 0, int base = 10);
strings.tex:775:  long long stoll(const wstring& str, size_t* idx = 0, int base = 10);
strings.tex:776:  unsigned long long stoull(const wstring& str, size_t* idx = 0, int base = 10);
strings.tex:777:  float stof(const wstring& str, size_t* idx = 0);
strings.tex:778:  double stod(const wstring& str, size_t* idx = 0);
strings.tex:779:  long double stold(const wstring& str, size_t* idx = 0);
strings.tex:4362:int stoi(const string& str, size_t* idx = 0, int base = 10);
strings.tex:4363:long stol(const string& str, size_t* idx = 0, int base = 10);
strings.tex:4364:unsigned long stoul(const string& str, size_t* idx = 0, int base = 10);
strings.tex:4365:long long stoll(const string& str, size_t* idx = 0, int base = 10);
strings.tex:4366:unsigned long long stoull(const string& str, size_t* idx = 0, int base = 10);
strings.tex:4396:float stof(const string& str, size_t* idx = 0);
strings.tex:4397:double stod(const string& str, size_t* idx = 0);
strings.tex:4398:long double stold(const string& str, size_t* idx = 0);
strings.tex:4459:int stoi(const wstring& str, size_t* idx = 0, int base = 10);
strings.tex:4460:long stol(const wstring& str, size_t* idx = 0, int base = 10);
strings.tex:4461:unsigned long stoul(const wstring& str, size_t* idx = 0, int base = 10);
strings.tex:4462:long long stoll(const wstring& str, size_t* idx = 0, int base = 10);
strings.tex:4463:unsigned long long stoull(const wstring& str, size_t* idx = 0, int base = 10);
strings.tex:4491:float stof(const wstring& str, size_t* idx = 0);
strings.tex:4492:double stod(const wstring& str, size_t* idx = 0);
strings.tex:4493:long double stold(const wstring& str, size_t* idx = 0);
templates.tex:2882:template<class T, class U> void f(U, A<U, T>* p = 0); // \#1
templates.tex:2883:template<         class U> void f(U, A<U, U>* p = 0); // \#2
templates.tex:5069:char* p = 0;

I'd be happy to provide a patch for this.

Eelis · 2016-07-30T17:26:59Z

Ah, and most of these should be replaced as well (egrep "\* *\) *0" *.tex):

compatibility.tex:257:p = (void*)(struct x {int i;} *)0;
declarators.tex:1654:template <class T, class U> decltype((*(T*)0) + (*(U*)0)) add(T t, U u);
expressions.tex:2266:  static_cast<D*>((B*)0);               // Error: B is a private base of D.
expressions.tex:2267:  static_cast<int B::*>((int D::*)0);   // Error: B is a private base of D.
expressions.tex:2415:\tcode{(void*)0} to the integral type. \begin{note} A \tcode{reinterpret_cast}
support.tex:88:\tcode{(void*)0}.}
templates.tex:2888:  f<int>(42, (A<int, int>*)0);                        // calls \#2

Eelis · 2016-07-30T17:50:38Z

Hmm 0 as a nullptr appears in various other contexts as well, and not all uses of 0 as a nullptr should be replaced, so now I'm just going over all occurrences of 0 in the standard, preparing a patch.

jensmaurer · 2016-11-13T20:54:23Z

Is there any progress on the patch?

faisalv · 2016-11-14T00:42:16Z

Just out of curiosity, what's the rationale for putting any effort at all into replacing these 0's w nullptr?

Eelis · 2016-11-17T23:01:15Z

(I had a patch but retracted it, no progress from me on this item.)

jensmaurer · 2016-12-07T19:46:53Z

@faisalv: I presume we want to show "good" coding practice in the library parts of the standard. In contrast, we want to show a variety of coding styles in the core parts of the standard, avoiding core endorsement of a particular one.

jensmaurer · 2016-12-14T19:34:30Z

Do we want to replace 0 with nullptr in the library sections of the standard?

jensmaurer · 2017-03-02T06:15:14Z

Editorial meeting consensus: Agreed with "Do we want to replace 0 with nullptr in the library sections of the standard?"

jensmaurer · 2017-03-29T18:14:26Z

Updated wiki page.

Fixes cplusplus#208.

Fixes #208.

jwakely self-assigned this Aug 5, 2014

jensmaurer added the big An issue causing a large set of changes, scattered across most of the text. label Nov 13, 2016

jensmaurer added the decision-required A decision of the editorial group (or the Project Editor) is required. label Dec 14, 2016

jensmaurer removed the decision-required A decision of the editorial group (or the Project Editor) is required. label Mar 2, 2017

jensmaurer added a commit to jensmaurer/draft that referenced this issue Mar 29, 2017

[lib] Use nullptr, not 0, for null pointer values.

c9e0d4d

Fixes cplusplus#208.

jensmaurer mentioned this issue Mar 29, 2017

[lib] Use nullptr, not 0, for null pointer values. #1586

Merged

jensmaurer assigned jensmaurer and unassigned jwakely Mar 29, 2017

jensmaurer added a commit to jensmaurer/draft that referenced this issue Mar 31, 2017

[lib] Use nullptr, not 0, for null pointer values.

23c9ef2

Fixes cplusplus#208.

tkoeppe closed this as completed in #1586 Mar 31, 2017

tkoeppe pushed a commit that referenced this issue Mar 31, 2017

[lib] Use nullptr, not 0, for null pointer values. (#1586)

dff391e

Fixes #208.

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Use nullptr in code blocks #208

Use nullptr in code blocks #208

sdutoit commented Oct 3, 2013

sdutoit commented Oct 3, 2013

sdutoit commented Oct 3, 2013

Eelis commented Jul 30, 2016 •

edited

Eelis commented Jul 30, 2016

Eelis commented Jul 30, 2016

jensmaurer commented Nov 13, 2016

faisalv commented Nov 14, 2016

Eelis commented Nov 17, 2016

jensmaurer commented Dec 7, 2016

jensmaurer commented Dec 14, 2016

jensmaurer commented Mar 2, 2017

jensmaurer commented Mar 29, 2017

Use nullptr in code blocks #208

Use nullptr in code blocks #208

Comments

sdutoit commented Oct 3, 2013

sdutoit commented Oct 3, 2013

sdutoit commented Oct 3, 2013

Eelis commented Jul 30, 2016 • edited

Eelis commented Jul 30, 2016

Eelis commented Jul 30, 2016

jensmaurer commented Nov 13, 2016

faisalv commented Nov 14, 2016

Eelis commented Nov 17, 2016

jensmaurer commented Dec 7, 2016

jensmaurer commented Dec 14, 2016

jensmaurer commented Mar 2, 2017

jensmaurer commented Mar 29, 2017

Eelis commented Jul 30, 2016 •

edited