This test case enters an infinite loop attempting to evaluate a static_assert involving an object ultimately initialized from a multi-dimensional array. static_assert(x,y) examines x to determine whether it can be shown to be true at compile time. If x is an expression involving a variable, it must examine the definition of that variable to determine if it has a known value at compile time. If that variable is defined in terms of another variable, it too must be examined, and so on. If at any point in this chain of definitions one of the variables is a multi-dimensional array, the compiler will probably enter an infinite loop trying to evaluate the static assertion.