void fill(const_reference value);
SPROUT_CONSTEXPR array fill(const_reference value) const;
#include <sprout/array.hpp>
#include <sprout/assert.hpp>
using namespace sprout;
auto x = array<int, 10>{{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}};
x.fill(0);
SPROUT_ASSERT_MSG(x[0] = 0, "filled with 0.");
#include <sprout/array.hpp>
using namespace sprout;
SPROUT_STATIC_CONSTEXPR auto x = array<int, 10>{{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}};
SPROUT_STATIC_CONSTEXPR auto y = x.fill(0);
static_assert(y[0] = 0, "filled with 0.");