can't pass array to to function

[nuderobmonkey]

Why don't this match together?

void fnc( int ** arr) { }

int main()
{
    int arr[2][3];
    
    fnc( arr );
}

Here the compiler error:

error: no matching function for call to 'fnc'
    fnc( arr );
    ^~~
arrtest.cpp:1:6: note: candidate function not viable: no known conversion from
      'int [2][3]' to 'int **' for 1st argument
void fnc( int ** arr) { }
     ^

[koothkeeper]

You will need to cast your function call to match your function definition.

[nuderobmonkey]

But I thought, an array will be passed as pointer. Why doesn't match this pointer to the array signature? And how need I cast the argument at the function call?

[koothkeeper]

Well, the hint is in the compiler's message: the argument you are passing is a two-dimensional array of integers, and the compiler wants int **.

So look here to see if this helps: http://www.cplusplus.com/doc/tutorial/typecasting/

[nuderobmonkey]

Yes, a cast to 'int**' works. But i thought, int[][] and int** would be the same thing for a function signature, because the int[][] will implicitly convertet to int** inside the function. I wonder why this isn't so.

[koothkeeper]

I think because using the stl containers are better solutions than "C"-style arrays?

[nuderobmonkey]

That could be. When I compile my example with a C-compiler, I get a warning instead of an error.