Use template to measure size of array

[stereoMatching]

At first, I wrote something like this

template<typename T, size_t size>
inline size_t const sizeof_array(T const [size]){return size;}

but it failed, then I find a solution form the other place, like this.

template<typename T, size_t size>
inline size_t const sizeof_array(T const (&)[size]){return size;}

what is the meaning of (&)? Why version one fail?
Thanks a lot

[sohguanh]

template<typename T, size_t size>
inline size_t const sizeof_array(T const (&varname)[size]){return size;}

I put in varname to make it easier to read. It is still the same protoype function. Basically it says the argument should be a variable that is an array of length size and the elements inside the array is of type T.

But I am still a bit confused why need the const keyword. I would presume it says inside the function sizeof_array, the variable varname cannot be made to point to other memory location ?