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Re: Macro replacement interpretation

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On 04/01/2015 06:38 PM, Jakob Bohm wrote:
>
> On 31/03/2015 23:38, James Kuyper wrote:
>
>>
>> On 03/30/2015 02:21 PM, Edward Diener wrote:
>>
>>>
>>> On 3/29/2015 5:01 AM, Jakob Bohm wrote:
...
>>>>  Thus it might be
>>>> cumbersome to use the standard syntax to implement
>>>> int printf(const char *fmt, ...) as a macro that invokes
>>>> int fprintf_private(FILE *f, const char *fmt, size_t fmtlen, ...).
...
>> In order for printf() to be defined as macro that calls
>> fprintf_private() while allowing it be called with only a format string
>> (as is legal), it would have to look something like this:
>>
>> // Remove any pre-existing #define of printf() by the implementation.
>> #undef printf
>> #define printf(...) fprintf_private(stdout, \\
>>          count_va_args(#__VA_ARGS__), __VA_ARGS__)
>>
>>
> Naah, I wanted to pass the length of the format string (in chars), not
> the argument count, to illustrate use of the actual last mandatory
> argument.

In that case, then it's much simpler: replace count_va_args() with
sizeof or strlen(). The only clue in your message was the fact that the
parameter's name was "fmtlen".

> Which was exactly my point.

I was responding to Edward Diener, explaining your point. I often do
that if the person who made the point hasn't gotten around to responding
yet. I apologize if you would have preferred to explain it yourself - I
sometimes get impatient - but sometimes such arguments carry more weight
if they are made by multiple people. Sometimes it helps to explain the
same thing multiple different ways.


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Macro replacement interpretation Edward Diener <eldiener@tropicsoft.invalid> - 2015-03-26 12:09 -0600
  Re: Macro replacement interpretation James Kuyper <jameskuyper@verizon.net> - 2015-03-27 14:07 -0600
  Re: Macro replacement interpretation Jakob Bohm <jb-usenet@wisemo.com> - 2015-03-29 03:01 -0600
    Re: Macro replacement interpretation Francis Glassborow <francis.glassborow@btinternet.com> - 2015-03-30 12:20 -0600
    Re: Macro replacement interpretation Edward Diener <eldiener@tropicsoft.invalid> - 2015-03-30 12:21 -0600
      Re: Macro replacement interpretation Francis Glassborow <francis.glassborow@btinternet.com> - 2015-03-31 15:39 -0600
        Re: Macro replacement interpretation James Kuyper <jameskuyper@verizon.net> - 2015-04-01 16:39 -0600
      Re: Macro replacement interpretation James Kuyper <jameskuyper@verizon.net> - 2015-03-31 15:38 -0600
        Re: Macro replacement interpretation Jakob Bohm <jb-usenet@wisemo.com> - 2015-04-01 16:38 -0600
          Re: Macro replacement interpretation James Kuyper <jameskuyper@verizon.net> - 2015-04-02 13:24 -0600
            Re: Macro replacement interpretation Francis Glassborow <francis.glassborow@btinternet.com> - 2015-04-03 14:30 -0600
        Re: Macro replacement interpretation Edward Diener <eldiener@tropicsoft.invalid> - 2015-04-03 14:30 -0600
          Re: Macro replacement interpretation James Kuyper <jameskuyper@verizon.net> - 2015-04-04 15:50 -0600

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