Sprout/sprout/optional/hash.hpp

22 lines
497 B
C++

#ifndef SPROUT_OPTIONAL_HASH_HPP
#define SPROUT_OPTIONAL_HASH_HPP
#include <cstddef>
#include <sprout/config.hpp>
#include <sprout/functional/hash/hash.hpp>
#include <sprout/optional/optional.hpp>
namespace sprout {
//
// hash_value
//
template<typename T>
inline SPROUT_CONSTEXPR std::size_t
hash_value(sprout::optional<T> const& v) {
return v.is_initialized() ? sprout::to_hash(*v)
: 0
;
}
} // namespace sprout
#endif // #ifndef SPROUT_OPTIONAL_HASH_HPP