compiler warning on 64bits gcc

Hi

File is_complete.hpp make warning in line 47:

template
struct ok_tag { double d; char c[N]; };
template
ok_tag check_is_complete(int);

specialization ok_tag check_is_complete(int); make implicit cast from unsigned long long (size_t is unsigned long long on 64 arch) to unsigned (32bits) and ugly warning on output.
It may be easy overcome and make more portable by:

template
struct ok_tag { double d; char c[N]; };