Re: Number of strings in an array.

From:
"Igor Tandetnik" <itandetnik@mvps.org>
Newsgroups:
microsoft.public.vc.language
Date:
Mon, 7 Apr 2008 15:08:27 -0400
Message-ID:
<#$76DLOmIHA.3636@TK2MSFTNGP02.phx.gbl>
goodTweetieBird <goodTweetieBird@hotmail.com> wrote:

The following snippet works because I know that there are three
strings in the array. How would one dynamically determine the number
of variable length strings in the array?

char* arr[] = {"string1", "string22","string333"};


#define count_of(a) (sizeof((a)) / sizeof((a)[0]))

int count = count_of(arr);

Works for arrays of all types (but unfortunately also compiles when
given a pointer, producing meaningless result). Some libraries use a
fancier macro, along these lines:

template <typename T, size_t N>
char (&array_size_helper(T (&arr)[N]))[N];

#define array_size(a) sizeof(array_size_helper((a)))

This fails to compile when given anything other than an array.
--
With best wishes,
    Igor Tandetnik

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