In a function declaration, what does passing a fixed size array signify? [duplicate]

Answer 1

I always though that passing fixed size C++ arrays was a "half baked" feature of C++. For example, ignored size matching or only being able to specify the first index size, etc... Until recently I learn this idiom:

template // enable_if magic can be added as well
function(double(&m)[N1][N2]){
  ... do something with array m...knowing its size!
}

Reference: Can someone explain this template code that gives me the size of an array?