PLC/vPLC>> CharConv>> 返回
项目作者： rigtorp

项目描述 ：
Fast integer to string and string to integer conversion functions
高级语言： C++
项目地址: git://github.com/rigtorp/CharConv.git
创建时间： 2017-12-26T21:24:44Z
项目社区：https://github.com/rigtorp/CharConv
开源协议：MIT License
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CharConv.h

License

Fast integer to string and string to integer conversion functions.

Usage

CharConv.h exposes two functions: to_chars and from_chars. The API is
similar, but not identical to that of
to_chars and
from_chars in the C++17
standard.

  • to_chars_result to_chars(char *first, char *last, int32_t value) noexcept
  • to_chars_result to_chars(char *first, char *last, uint32_t value) noexcept
  • to_chars_result to_chars(char *first, char *last, int64_t value) noexcept

  • to_chars_result to_chars(char *first, char *last, uint64_t value) noexcept

    Converts value into characters in base 10.

  • from_chars_result from_chars(const char *first, const char *last, int32_t &value) noexcept

  • from_chars_result from_chars(const char *first, const char *last, uint32_t &value) noexcept
  • from_chars_result from_chars(const char *first, const char *last, int64_t &value) noexcept

  • from_chars_result from_chars(const char *first, const char *last, uint64_t &value) noexcept

    Converts the character sequence [first, last] representing
    a base 10 number to an integer value.

Example

  1. using namespace rigtorp;
  3. std::array<char, 32> buf = {};
  4. to_chars(buf.begin(), buf.end(), 123));
  5. std::cout << buf.data();
  7. int result;
  8. from_chars(buf.begin(), buf.end(), result);
  9. std::cout << result;

Benchmark

Running on Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz:

  1. 2017-12-26 15:08:09
  2. Run on (32 X 3000 MHz CPU s)
  3. CPU Caches:
  4.   L1 Data 32K (x16)
  5.   L1 Instruction 32K (x16)
  6.   L2 Unified 256K (x16)
  7.   L3 Unified 20480K (x2)
  8. -----------------------------------------------------------------
  9. Benchmark                          Time           CPU Iterations
  10. -----------------------------------------------------------------
  11. BM_sprintf/1                      73 ns         73 ns    9625985
  12. BM_sprintf/2                      75 ns         75 ns    9284410
  13. BM_sprintf/3                      77 ns         77 ns    9135939
  14. BM_sprintf/4                      79 ns         79 ns    8868328
  15. BM_sprintf/5                      80 ns         80 ns    8716034
  16. BM_sprintf/6                      82 ns         82 ns    8561608
  17. BM_sprintf/7                      83 ns         83 ns    8426476
  18. BM_sprintf/8                      85 ns         85 ns    8219398
  19. BM_sprintf/9                      87 ns         87 ns    8016940
  20. BM_to_string/1                    76 ns         76 ns    9159664
  21. BM_to_string/2                    79 ns         79 ns    8852605
  22. BM_to_string/3                    81 ns         81 ns    8612168
  23. BM_to_string/4                    83 ns         83 ns    8388007
  24. BM_to_string/5                    85 ns         85 ns    8289128
  25. BM_to_string/6                    86 ns         86 ns    8124345
  26. BM_to_string/7                    87 ns         87 ns    8049160
  27. BM_to_string/8                    89 ns         89 ns    7870350
  28. BM_to_string/9                    90 ns         90 ns    7744079
  29. BM_stringstream/1                 34 ns         34 ns   20586984
  30. BM_stringstream/2                 38 ns         38 ns   18778128
  31. BM_stringstream/3                 39 ns         39 ns   17165452
  32. BM_stringstream/4                 43 ns         43 ns   16696859
  33. BM_stringstream/5                 45 ns         45 ns   16127302
  34. BM_stringstream/6                 47 ns         47 ns   15600041
  35. BM_stringstream/7                 51 ns         51 ns   10000000
  36. BM_stringstream/8                 51 ns         51 ns   13379508
  37. BM_stringstream/9                 55 ns         55 ns   12981355
  38. BM_to_chars_naive/1               12 ns         12 ns   58830826
  39. BM_to_chars_naive/2               14 ns         14 ns   51283290
  40. BM_to_chars_naive/3               15 ns         15 ns   47083964
  41. BM_to_chars_naive/4               16 ns         16 ns   43907170
  42. BM_to_chars_naive/5               17 ns         17 ns   41087032
  43. BM_to_chars_naive/6               18 ns         18 ns   38062908
  44. BM_to_chars_naive/7               19 ns         19 ns   36324383
  45. BM_to_chars_naive/8               21 ns         21 ns   33114607
  46. BM_to_chars_naive/9               22 ns         22 ns   31397235
  47. BM_to_chars/1                      9 ns          9 ns   77857609
  48. BM_to_chars/2                     10 ns         10 ns   71753282
  49. BM_to_chars/3                     11 ns         11 ns   54759461
  50. BM_to_chars/4                     12 ns         12 ns   56404502
  51. BM_to_chars/5                     14 ns         14 ns   50743796
  52. BM_to_chars/6                     15 ns         15 ns   47294406
  53. BM_to_chars/7                     16 ns         16 ns   43201370
  54. BM_to_chars/8                     18 ns         18 ns   39207877
  55. BM_to_chars/9                     20 ns         20 ns   35792902
  56. BM_atoi/1                         14 ns         14 ns   48904147
  57. BM_atoi/2                         16 ns         16 ns   42837308
  58. BM_atoi/3                         18 ns         18 ns   39150309
  59. BM_atoi/4                         20 ns         20 ns   35951644
  60. BM_atoi/5                         21 ns         21 ns   33153980
  61. BM_atoi/6                         23 ns         23 ns   30722978
  62. BM_atoi/7                         24 ns         24 ns   28734136
  63. BM_atoi/8                         26 ns         26 ns   26651732
  64. BM_atoi/9                         28 ns         28 ns   25124905
  65. BM_strtol/1                       14 ns         15 ns   48394136
  66. BM_strtol/2                       16 ns         16 ns   42688678
  67. BM_strtol/3                       18 ns         18 ns   39113890
  68. BM_strtol/4                       20 ns         20 ns   35940516
  69. BM_strtol/5                       21 ns         21 ns   33045007
  70. BM_strtol/6                       23 ns         23 ns   30704735
  71. BM_strtol/7                       24 ns         24 ns   28600808
  72. BM_strtol/8                       26 ns         26 ns   26730526
  73. BM_strtol/9                       28 ns         28 ns   25050583
  74. BM_stoi/1                         16 ns         16 ns   44890941
  75. BM_stoi/2                         17 ns         17 ns   40451418
  76. BM_stoi/3                         19 ns         19 ns   37593651
  77. BM_stoi/4                         20 ns         20 ns   34442293
  78. BM_stoi/5                         22 ns         22 ns   31927689
  79. BM_stoi/6                         24 ns         24 ns   29465662
  80. BM_stoi/7                         25 ns         25 ns   27752163
  81. BM_stoi/8                         27 ns         27 ns   25848348
  82. BM_stoi/9                         29 ns         29 ns   24381987
  83. BM_from_chars_unchecked/1          4 ns          4 ns  162408633
  84. BM_from_chars_unchecked/2          5 ns          5 ns  132550992
  85. BM_from_chars_unchecked/3          6 ns          6 ns  113085260
  86. BM_from_chars_unchecked/4          7 ns          7 ns   96808997
  87. BM_from_chars_unchecked/5          8 ns          8 ns   89169648
  88. BM_from_chars_unchecked/6          8 ns          8 ns   82540712
  89. BM_from_chars_unchecked/7          9 ns          9 ns   77455690
  90. BM_from_chars_unchecked/8         10 ns         10 ns   73136554
  91. BM_from_chars_unchecked/9         10 ns         10 ns   68730597
  92. BM_from_chars/1                    9 ns          9 ns   78818376
  93. BM_from_chars/2                   10 ns         10 ns   71176282
  94. BM_from_chars/3                   11 ns         11 ns   63257070
  95. BM_from_chars/4                   12 ns         12 ns   56995175
  96. BM_from_chars/5                   14 ns         14 ns   50584861
  97. BM_from_chars/6                   15 ns         15 ns   47135520
  98. BM_from_chars/7                   16 ns         16 ns   43457090
  99. BM_from_chars/8                   17 ns         17 ns   40382499
  100. BM_from_chars/9                   19 ns         19 ns   37375537

About

This project was created by Erik Rigtorp
[erik@rigtorp.se](mailto:erik@rigtorp.se).