foedus::assorted::Hex Struct Reference

Convenient way of writing hex integers to stream. More...

Detailed Description

Convenient way of writing hex integers to stream.

Use it as follows.

std::cout << Hex(1234) << ...
// same output as:
// std::cout << "0x" << std::hex << std::uppercase << 1234 << std::nouppercase << std::dec << ...

Definition at line 124 of file assorted_func.hpp.

#include <assorted_func.hpp>

Public Member Functions
template<typename T >
	Hex (T val, int fix_digits=-1)

Public Attributes
uint64_t	val_
int	fix_digits_

Friends
std::ostream &	operator<< (std::ostream &o, const Hex &v)

Constructor & Destructor Documentation

template<typename T >

foedus::assorted::Hex::Hex ( T  val, int  fix_digits = -1  )

inline

Definition at line 126 of file assorted_func.hpp.

: val_(static_cast<uint64_t>(val)), fix_digits_(fix_digits) {}

Friends And Related Function Documentation

std::ostream& operator<< ( std::ostream &  o, const Hex &  v  )

friend

Definition at line 92 of file assorted_func.cpp.

                                                    {
  // Duh, even if I recover the flags, not good to contaminate the given ostream object.
  // std::ios::fmtflags old_flags = o.flags();
  // o << "0x";
  // if (v.fix_digits_ >= 0) {
  //   o.width(v.fix_digits_);
  //   o.fill('0');
  // }
  // o << std::hex << std::uppercase << v.val_;
  // o.flags(old_flags);

  // Let's do it ourselves
  char buffer[17];
  buffer[16] = 0;
  for (uint16_t i = 0; i < 16U; ++i) {
    buffer[i] = kUpperHexChars[(v.val_ >> ((15 - i) * 4)) & 0xFU];
  }
  uint16_t start_pos;
  for (start_pos = 0; start_pos < 15U; ++start_pos) {
    if (buffer[start_pos] != '0') {
      break;
    }
    if (v.fix_digits_ >= 0 && start_pos > 16 - v.fix_digits_) {
      break;
    }
  }

  o << "0x" << (buffer + start_pos);
  return o;
}

Member Data Documentation

int foedus::assorted::Hex::fix_digits_

Definition at line 129 of file assorted_func.hpp.

Referenced by foedus::assorted::operator<<().

uint64_t foedus::assorted::Hex::val_

Definition at line 128 of file assorted_func.hpp.

Referenced by foedus::assorted::operator<<().

---

The documentation for this struct was generated from the following file:

• /home/shino/foedus_code/foedus-core/include/foedus/assorted/assorted_func.hpp