size function for multi-dimensional array?

[Nancy Keuss]

Hi, is there a function that returns the dimensions of, say, a
two-dimensional array in c++?

Thanks,
N.

[osmium]

Nancy Keuss writes:

Hi, is there a function that returns the dimensions of, say, a
two-dimensional array in c++?

Since C++ doesn't have two-dimensional arrays, the answer is no. In C++
one creates the *illusion* of two-dimensional arrays.

[Ron Natalie]

"osmium" <r1********@comcast.net> wrote in message news:bu************@ID-179017.news.uni-berlin.de...

Nancy Keuss writes:

Hi, is there a function that returns the dimensions of, say, a
two-dimensional array in c++?

Since C++ doesn't have two-dimensional arrays, the answer is no. In C++
one creates the *illusion* of two-dimensional arrays.

Correct, you have an array of arrays.

[Nick Hounsome]

"Nancy Keuss" <mu*****@aol.com> wrote in message
news:d0**************************@posting.google.c om...

Hi, is there a function that returns the dimensions of, say, a
two-dimensional array in c++?

Thanks,
N.

If the compiler knows the first dimension then you might be able to use the
same trick as for 1D:

int a[M][N];

assert(sizeof(a)/sizeof(a[0]) == M);
assert(sizeof(a[0])/sizeof(a[0][0]) == N);

[Jeff Schwab]

Nancy Keuss wrote:

Hi, is there a function that returns the dimensions of, say, a
two-dimensional array in c++?

Thanks,
N.

#include <cstddef>
#include <utility>

typedef std::pair< std::size_t, std::size_t > Dimension_Pair;

template< typename T, std::size_t n, std::size_t m >
Dimension_Pair get_dimensions( T (&)[ n ][ m ] )
{
return Dimension_Pair( n, m );
}

#include <iostream>

int main( )
{
char c[ 3 ][ 5 ];

Dimension_Pair dimensions = get_dimensions( c );

std::cout << dimensions.first << ", " << dimensions.second
<< '\n';
}