static SPROUT_CONSTEXPR char_type const* find(char_type const* s, std::size_t n, char_type const& a);
#include <sprout/string.hpp>
#include <sprout/iterator.hpp>
using namespace sprout;
SPROUT_STATIC_CONSTEXPR char const* x = "homuhomu";
SPROUT_STATIC_CONSTEXPR auto result = char_traits<char>::find(x, 8, 'm');
static_assert(sprout::distance(x, result) == 2, "a found position is 2.");