Name of C/C++ stdlib naming convention?

Question

I wonder if the naming convention used in C/C++ standard libraries has a name, or at least a cheat-sheet where I can lookup the rules. E.g.

push_back    -- underscore used
setstate     -- but not used here!
string::npos -- when to use abbreviations?
fprintf
...

Does the naming convention used in the C/C++ standard libraries have a specific name?

Also, the weird upper case letter of `std::ios_base::Init` o_O — Johannes Schaub - litb, Nov 14 '09 at 13:52
It's called "Whatever shit we happened to come up with this week". — Paul Tomblin, Nov 14 '09 at 14:01
Rob Pike, who was involved in the early history of C, has this to say about variable names, which you might find interesting: http://doc.cat-v.org/bell_labs/pikestyle — , Dec 03 '09 at 01:03
Perhaps we should distinguish between C and C++ standard libraries? — GooseDeveloper, Oct 07 '21 at 18:36

Charles Salvia · Answer 1 · 2009-11-14T14:12:34.340

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C/C++ uses the famous make-stuff-up-as-we-go-along naming convention. In general, the only consistent things you can say about the C/C++ standard library naming convention is that it doesn't use camel case (except for C++ STL template typenames), it uses lower-case class and function names, and (sometimes) uses underscores to separate words. But the usage of underscores is more of a C++ thing; C in particular tends to abbreviate words, e.g. strlen, memcpy. This is probably a result of the tendency to use very terse names for things in the early days of UNIX.

edited Nov 14 '09 at 14:12

answered Nov 14 '09 at 14:01

Charles Salvia

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"tendency to use very terse names for things" which is either due to 80-char or smaller terminals; resource limits on compilers; an innate desire to Huffman encode the universe; or all of the above. – Steve Jessop Nov 14 '09 at 15:32
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Pre-ansi compilers only considered the first 6 characters of a symbol to be salient in order to be compatible with Fortran, IIRC, so the symbols `strlen`, `strlenxyz`, and `strlenohmygodwhathaveidone` all referred to the same thing. So, for compatibility with pre-ANSI compilers, the ANSI C standard made sure the first 6 characters of all standard library symbols were unique among each other. – Adam Rosenfield Dec 03 '09 at 01:13

score 9 · Answer 2 · answered Nov 14 '09 at 14:25

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The C standard library has well defined rules you must follow to avoid name conficts. I don't know anything about C++ though.

If you think this is a mess you should check out the PHP library...

answered Nov 14 '09 at 14:25

ntd

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+1 for the link. More names are reserved than you realize, for example types ending in `_t`. – u0b34a0f6ae Nov 14 '09 at 14:30
@kaizer: afaik reserving `_t` is a POSIX restriction – Christoph Nov 14 '09 at 15:00
Yeah. C only reserves those that start with `uint` or `int` and end with `_t`. – Johannes Schaub - litb Nov 14 '09 at 16:09

score 6 · Answer 3 · answered Nov 14 '09 at 14:04

I think there are several groups invented at different times by different people and using somewhat different conventions: C libraries, streams, strings, STL (containers + algorithms + iterators). I have a feeling that the latter might be seen as the convention, which sets the example for things like boost and C++0x naming.

score 4 · Answer 4 · answered Nov 14 '09 at 13:52

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The sad truth is - there is no real convention.

See the argument order of stdio functions as a painful reminder.

answered Nov 14 '09 at 13:52

Eli Bendersky

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There is a good reason for those, actually. With the traditional C function call ABI, calling multiple functions with the same last argument (i.e. `for (i = 0; i < n; i++) { fputs(s[i], stdout); fputc('\n', stdout; }` is cheaper than if it were the first argument non-changing. However, for variadic functions like `printf`, the fixed arguments must go at the start of the argument list. – ephemient Nov 14 '09 at 20:58

score 0 · Answer 5 · answered Nov 14 '09 at 13:53

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I don't have the answer, but at least, I don't think that C and C++ use the same naming convention.

answered Nov 14 '09 at 13:53

Soufiane Hassou

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Things like fprintf, strlen, itoa (shudder) come from C libraries. Those have the convention of lower-case, no underscores and heavy abbreviating. The C libraries are the ones beginning with "c" in C++: cstdio, cstring, cmath etc. – UncleBens Nov 14 '09 at 14:12
How `C` has a name `strpbrk` and `C++` has a name `sync_with_stdio`, and not `swstdio` :) – Johannes Schaub - litb Nov 14 '09 at 16:10

score 0 · Answer 6 · answered Nov 14 '09 at 16:40

I don't think there is a name for either set of naming conventions.

The naming conventions in the C and C++ standards are different, though faintly related.

In particular, in the C library, no function or macro name contains an underscore (AFAICR), unlike the C++ library.

Most of the C library naming convention was controlled by precedent; it standardized existing practice (as of about 1984), with remarkably few inventions (locale handling via <locale.h> being the main one).

The C++ library was based on precedent too - but a different set of precedents, and I think it is arguable that the STL was not in as widespread use prior to its adoption by the standard as the functions in the C library were.

Name of C/C++ stdlib naming convention?

6 Answers6

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