format_int Class Reference

#include <format.h>

Public Member Functions
	format_int (int value)
	format_int (long value)
	format_int (long long value)
	format_int (unsigned value)
	format_int (unsigned long value)
	format_int (unsigned long long value)
std::size_t	size () const
const char *	data () const
const char *	c_str () const
std::string	str () const

Private Types
enum	{ BUFFER_SIZE = std::numeric_limits<unsigned long long>::digits10 + 3 }

Private Member Functions
char *	format_decimal (unsigned long long value)
void	format_signed (long long value)

Private Attributes
char	buffer_ [BUFFER_SIZE]
char *	str_

Detailed Description

Fast integer formatter.

Definition at line 2813 of file format.h.

Member Enumeration Documentation

anonymous enum

private

Enumerator
BUFFER_SIZE

Definition at line 2817 of file format.h.

{BUFFER_SIZE = std::numeric_limits<unsigned long long>::digits10 + 3};

Constructor & Destructor Documentation

format_int::format_int ( int  value )

inlineexplicit

Definition at line 2854 of file format.h.

{ format_signed(value); }

format_int::format_int ( long  value )

inlineexplicit

Definition at line 2855 of file format.h.

{ format_signed(value); }

format_int::format_int ( long long  value )

inlineexplicit

Definition at line 2856 of file format.h.

{ format_signed(value); }

format_int::format_int ( unsigned  value )

inlineexplicit

Definition at line 2857 of file format.h.

: str_(format_decimal(value)) {}

format_int::format_int ( unsigned long  value )

inlineexplicit

Definition at line 2858 of file format.h.

: str_(format_decimal(value)) {}

format_int::format_int ( unsigned long long  value )

inlineexplicit

Definition at line 2859 of file format.h.

: str_(format_decimal(value)) {}

Member Function Documentation

const char* format_int::c_str ( ) const

inline

Returns a pointer to the output buffer content with terminating null character appended.

Definition at line 2876 of file format.h.

                            {
    buffer_[BUFFER_SIZE - 1] = '\0';
    return str_;
  }

const char* format_int::data ( ) const

inline

Returns a pointer to the output buffer content. No terminating null character is appended.

Definition at line 2870 of file format.h.

{ return str_; }

char* format_int::format_decimal ( unsigned long long  value )

inlineprivate

Definition at line 2822 of file format.h.

                                                 {
    char *ptr = buffer_ + (BUFFER_SIZE - 1);  // Parens to workaround MSVC bug.
    while (value >= 100) {
      // Integer division is slow so do it for a group of two digits instead
      // of for every digit. The idea comes from the talk by Alexandrescu
      // "Three Optimization Tips for C++". See speed-test for a comparison.
      unsigned index = static_cast<unsigned>((value % 100) * 2);
      value /= 100;
      *--ptr = internal::data::DIGITS[index + 1];
      *--ptr = internal::data::DIGITS[index];
    }
    if (value < 10) {
      *--ptr = static_cast<char>('0' + value);
      return ptr;
    }
    unsigned index = static_cast<unsigned>(value * 2);
    *--ptr = internal::data::DIGITS[index + 1];
    *--ptr = internal::data::DIGITS[index];
    return ptr;
  }

void format_int::format_signed ( long long  value )

inlineprivate

Definition at line 2843 of file format.h.

                                      {
    unsigned long long abs_value = static_cast<unsigned long long>(value);
    bool negative = value < 0;
    if (negative)
      abs_value = 0 - abs_value;
    str_ = format_decimal(abs_value);
    if (negative)
      *--str_ = '-';
  }

std::size_t format_int::size ( void  ) const

inline

Returns the number of characters written to the output buffer.

Definition at line 2862 of file format.h.

                         {
    return internal::to_unsigned(buffer_ - str_ + BUFFER_SIZE - 1);
  }

std::string format_int::str ( ) const

inline

Returns the content of the output buffer as an std::string.

Definition at line 2886 of file format.h.

{ return std::string(str_, size()); }

Member Data Documentation

char format_int::buffer_[BUFFER_SIZE]

mutableprivate

Definition at line 2818 of file format.h.

char* format_int::str_

private

Definition at line 2819 of file format.h.

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

• wire-cell-build/util/inc/spdlog/fmt/bundled/format.h