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/// \file utils/units.hpp
/// Formatters and parsers of user-friendly units.

#if !defined(UTILS_UNITS_HPP)
#define UTILS_UNITS_HPP

extern "C" {
#include <stdint.h>
}

#include <istream>
#include <ostream>
#include <string>

namespace utils {
namespace units {


namespace {

/// Constant representing 1 kilobyte.
const uint64_t KB = int64_t(1) << 10;

/// Constant representing 1 megabyte.
const uint64_t MB = int64_t(1) << 20;

/// Constant representing 1 gigabyte.
const uint64_t GB = int64_t(1) << 30;

/// Constant representing 1 terabyte.
const uint64_t TB = int64_t(1) << 40;

}  // anonymous namespace


/// Representation of a bytes quantity.
///
/// The purpose of this class is to represent an amount of bytes in a semantic
/// manner, and to provide functions to format such numbers for nice user
/// presentation and to parse back such numbers.
///
/// The input follows this regular expression: [0-9]+(|\.[0-9]+)[GgKkMmTt]?
/// The output follows this regular expression: [0-9]+\.[0-9]{3}[GKMT]?
class bytes {
    /// Raw representation, in bytes, of the quantity.
    uint64_t _count;

public:
    bytes(void);
    explicit bytes(const uint64_t);

    static bytes parse(const std::string&);
    std::string format(void) const;

    operator uint64_t(void) const;
};


std::istream& operator>>(std::istream&, bytes&);
std::ostream& operator<<(std::ostream&, const bytes&);


}  // namespace units
}  // namespace utils

#endif  // !defined(UTILS_UNITS_HPP)