error: use of parameter outside function body before ] token c++
If you are using GCC, then you are to pass the length of the array
as a parameter to the function.
void foo (int m, int arr[][m]) {
//...
}
However, there seems to be a bug in either the compiler or
the documentation, as the above function prototype syntax
only works when compiling C code, not C++ (as of gcc version 4.8.2).
The only work-around I found was to use a void * parameter,
and cast it int the function body:
int foo_workaround (int m, void *x)
{
int (*arr)[m] = static_cast<int (*)[m]>(x);
//...
}
There are other solutions if you do not want to rely on a compiler
extension. If you don't mind a separate allocation for each row,
you can use a vector of vectors, for example:
std::vector<std::vector<int> > arr(n, std::vector<int>(m));