Libosmium  2.16.0
Fast and flexible C++ library for working with OpenStreetMap data
double.hpp
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1 #ifndef OSMIUM_UTIL_DOUBLE_HPP
2 #define OSMIUM_UTIL_DOUBLE_HPP
3 
4 /*
5 
6 This file is part of Osmium (https://osmcode.org/libosmium).
7 
8 Copyright 2013-2021 Jochen Topf <jochen@topf.org> and others (see README).
9 
10 Boost Software License - Version 1.0 - August 17th, 2003
11 
12 Permission is hereby granted, free of charge, to any person or organization
13 obtaining a copy of the software and accompanying documentation covered by
14 this license (the "Software") to use, reproduce, display, distribute,
15 execute, and transmit the Software, and to prepare derivative works of the
16 Software, and to permit third-parties to whom the Software is furnished to
17 do so, all subject to the following:
18 
19 The copyright notices in the Software and this entire statement, including
20 the above license grant, this restriction and the following disclaimer,
21 must be included in all copies of the Software, in whole or in part, and
22 all derivative works of the Software, unless such copies or derivative
23 works are solely in the form of machine-executable object code generated by
24 a source language processor.
25 
26 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
29 SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
30 FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
31 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
32 DEALINGS IN THE SOFTWARE.
33 
34 */
35 
36 #include <algorithm>
37 #include <cassert>
38 #include <cstdio>
39 #include <iterator>
40 #include <string>
41 
42 namespace osmium {
43 
44  inline namespace util {
45 
55  template <typename T>
56  inline T double2string(T iterator, double value, int precision) {
57  assert(precision <= 17);
58 
59  enum {
60  max_double_length = 20 // should fit decimal representation of any double
61  };
62 
63  char buffer[max_double_length];
64 
65 #ifndef _MSC_VER
66  int len = snprintf(buffer, max_double_length, "%.*f", precision, value);
67 #else
68  int len = _snprintf(buffer, max_double_length, "%.*f", precision, value);
69 #endif
70  assert(len > 0 && len < max_double_length);
71 
72  while (buffer[len - 1] == '0') {
73  --len;
74  }
75  if (buffer[len - 1] == '.') {
76  --len;
77  }
78 
79  return std::copy_n(buffer, len, iterator);
80  }
81 
90  inline void double2string(std::string& out, double value, int precision) {
91  double2string(std::back_inserter(out), value, precision);
92  }
93 
94  } // namespace util
95 
96 } // namespace osmium
97 
98 #endif // OSMIUM_UTIL_DOUBLE_HPP
osmium::util::double2string
T double2string(T iterator, double value, int precision)
Definition: double.hpp:56
osmium
Namespace for everything in the Osmium library.
Definition: assembler.hpp:53