GEOS  3.10.0
util.h
1 /**********************************************************************
2  *
3  * GEOS - Geometry Engine Open Source
4  * http://geos.osgeo.org
5  *
6  * Copyright (C) 2001-2002 Vivid Solutions Inc.
7  * Copyright (C) 2006 Refractions Research Inc.
8  *
9  * This is free software; you can redistribute and/or modify it under
10  * the terms of the GNU Lesser General Public Licence as published
11  * by the Free Software Foundation.
12  * See the COPYING file for more information.
13  *
14  **********************************************************************
15  *
16  * Utility header to retain a bit of backward compatibility.
17  * Try to avoid including this header directly.
18  *
19  **********************************************************************/
20 
21 #ifndef GEOS_UTIL_H
22 #define GEOS_UTIL_H
23 
24 //#include <geos/util/AssertionFailedException.h>
25 #include <geos/util/GEOSException.h>
26 #include <geos/util/IllegalArgumentException.h>
27 #include <geos/util/TopologyException.h>
28 //#include <geos/util/UnsupportedOperationException.h>
29 //#include <geos/util/CoordinateArrayFilter.h>
30 //#include <geos/util/UniqueCoordinateArrayFilter.h>
31 #include <geos/util/GeometricShapeFactory.h>
32 //#include <geos/util/math.h>
33 
34 #include <memory>
35 #include <type_traits>
36 
37 //
38 // Private macros definition
39 //
40 
41 namespace geos {
42 template<class T>
43 void
44 ignore_unused_variable_warning(T const &) {}
45 
46 namespace detail {
47 #if __cplusplus >= 201402L
48 using std::make_unique;
49 #else
50 // Backport of std::make_unique to C++11
51 // Source: https://stackoverflow.com/a/19472607
52 template<class T>
53 struct _Unique_if {
54  typedef std::unique_ptr<T> _Single_object;
55 };
56 
57 template<class T>
58 struct _Unique_if<T[]> {
59  typedef std::unique_ptr<T[]> _Unknown_bound;
60 };
61 
62 template<class T, std::size_t N>
63 struct _Unique_if<T[N]> {
64  typedef void _Known_bound;
65 };
66 
67 template<class T, class... Args>
68 typename _Unique_if<T>::_Single_object
69 make_unique(Args &&... args) {
70  return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
71 }
72 
73 template<class T>
74 typename _Unique_if<T>::_Unknown_bound
75 make_unique(std::size_t n) {
76  typedef typename std::remove_extent<T>::type U;
77  return std::unique_ptr<T>(new U[n]());
78 }
79 
80 template<class T, class... Args>
81 typename _Unique_if<T>::_Known_bound
82 make_unique(Args &&...) = delete;
83 
84 #endif
85 
95 template<typename To, typename From> inline To down_cast(From* f)
96 {
97  static_assert(
98  (std::is_base_of<From,
99  typename std::remove_pointer<To>::type>::value),
100  "target type not derived from source type");
101 #if GEOS_DEBUG
102  assert(f == nullptr || dynamic_cast<To>(f) != nullptr);
103 #endif
104  return static_cast<To>(f);
105 }
106 
107 // Avoid "redundant move" warning when calling std::move() to return
108 // unique_ptr<Derived> from a function with return type unique_ptr<Base>
109 // The std::move is required for the gcc 4.9 series, which has not addressed
110 // CWG defect 1579 ("return by converting move constructor")
111 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#1579
112 #if __GNUC__ > 0 && __GNUC__ < 5
113 #define RETURN_UNIQUE_PTR(x) (std::move(x))
114 #else
115 #define RETURN_UNIQUE_PTR(x) (x)
116 #endif
117 
118 } // namespace detail
119 } // namespace geos
120 
121 #endif // GEOS_UTIL_H
Basic namespace for all GEOS functionalities.
Definition: Angle.h:26