Embedded Template Library  1.0
log.h
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1 
3 /******************************************************************************
4 The MIT License(MIT)
5 
6 Embedded Template Library.
7 https://github.com/ETLCPP/etl
8 https://www.etlcpp.com
9 
10 Copyright(c) 2014 jwellbelove
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30 
31 #ifndef ETL_LOG_INCLUDED
32 #define ETL_LOG_INCLUDED
33 
34 #include <stddef.h>
35 
36 #include "platform.h"
37 
43 
44 namespace etl
45 {
46  //***************************************************************************
53  //***************************************************************************
54  template <size_t NV, size_t BASE>
55  struct log
56  {
57  enum value_type
58  {
59  // Recursive definition.
60  value = (NV >= BASE) ? 1 + log<NV / BASE, BASE>::value : 0
61  };
62  };
63 
64  //***************************************************************************
65  // Specialisation for N = 1
66  //***************************************************************************
67  template <size_t BASE>
68  struct log<1, BASE>
69  {
70  enum value_type
71  {
72  value = 0
73  };
74  };
75 
76  //***************************************************************************
77  // Specialisation for N = 0
78  //***************************************************************************
79  template <size_t BASE>
80  struct log<0, BASE>
81  {
82  enum value_type
83  {
84  value = 0
85  };
86  };
87 
88 #if ETL_CPP17_SUPPORTED
89  template <size_t NV, size_t BASE>
90  inline constexpr size_t log_v = log<NV, BASE>::value;
91 #endif
92 
93  //***************************************************************************
96  //***************************************************************************
97  template <const size_t NV>
98  struct log2
99  {
100  enum value_type
101  {
102  value = log<NV, 2>::value
103  };
104  };
105 
106 #if ETL_CPP17_SUPPORTED
107  template <size_t NV>
108  inline constexpr size_t log2_v = log2<NV>::value;
109 #endif
110 
111  //***************************************************************************
114  //***************************************************************************
115  template <const size_t NV>
116  struct log10
117  {
118  enum value_type
119  {
120  value = log<NV, 10>::value
121  };
122  };
123 
124 #if ETL_CPP17_SUPPORTED
125  template <size_t NV>
126  inline constexpr size_t log10_v = log10<NV>::value;
127 #endif
128 }
129 
130 #endif
Definition: log.h:56
Definition: log.h:117
Definition: log.h:99
Definition: absolute.h:37