Re: std::copy implementation standard conforming?

The problem is not undefined behavior but the fact that template
parameter deduction does not do conversions that is

void bar(T[1] x);//1
void bar(T *x);//2
template <class T> foo(T x) {bar (x);}

char x[1];
char *y = x;

foo(x) ;// calls bar(char[1]);
foo(y) ;// calls bar(char *);

data->data is a a one byte array not a byte *. Cast is the solution
or a named temp like
    byte *out = data->data; // this does the conversion.
    std::copy(array.begin(),array.end(),out);