[ VIGRA Homepage | Function Index | Class Index | Namespaces | File List | Main Page ]

utilities.hxx VIGRA

Go to the documentation of this file.

1 /************************************************************************/
2 /* */
3 /* Copyright 1998-2002 by Ullrich Koethe */
4 /* */
5 /* This file is part of the VIGRA computer vision library. */
6 /* The VIGRA Website is */
7 /* http://hci.iwr.uni-heidelberg.de/vigra/ */
8 /* Please direct questions, bug reports, and contributions to */
9 /* ullrich.koethe@iwr.uni-heidelberg.de or */
10 /* vigra@informatik.uni-hamburg.de */
11 /* */
12 /* Permission is hereby granted, free of charge, to any person */
13 /* obtaining a copy of this software and associated documentation */
14 /* files (the "Software"), to deal in the Software without */
15 /* restriction, including without limitation the rights to use, */
16 /* copy, modify, merge, publish, distribute, sublicense, and/or */
17 /* sell copies of the Software, and to permit persons to whom the */
18 /* Software is furnished to do so, subject to the following */
19 /* conditions: */
20 /* */
21 /* The above copyright notice and this permission notice shall be */
22 /* included in all copies or substantial portions of the */
23 /* Software. */
24 /* */
25 /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND */
26 /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES */
27 /* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND */
28 /* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT */
29 /* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, */
30 /* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING */
31 /* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR */
32 /* OTHER DEALINGS IN THE SOFTWARE. */
33 /* */
34 /************************************************************************/
35 
36 
37 #ifndef VIGRA_BASICS_HXX
38 #define VIGRA_BASICS_HXX
39 
40 #include "config.hxx"
41 #include "error.hxx"
42 #include "metaprogramming.hxx"
43 #include "tuple.hxx"
44 #include "diff2d.hxx"
45 #include "mathutil.hxx"
46 #include <string>
47 #include <sstream>
48 #include <cctype>
49 
50 /*! \file */
51 
52 namespace vigra {
53 
54 /** Convert a value to a string. Available for integral and floating point types
55  and void *.
56 */
57 doxygen_overloaded_function(template <class T> std::string asString(T t))
58 
59 #define VIGRA_AS_STRING(T) \
60 inline std::string asString(T t) \
61 { \
62  std::stringstream s; \
63  s << t; \
64  return s.str(); \
65 }
66 
67 VIGRA_AS_STRING(bool)
68 VIGRA_AS_STRING(signed char)
69 VIGRA_AS_STRING(unsigned char)
70 VIGRA_AS_STRING(signed short)
71 VIGRA_AS_STRING(unsigned short)
72 VIGRA_AS_STRING(signed long)
73 VIGRA_AS_STRING(unsigned long)
74 VIGRA_AS_STRING(signed long long)
75 VIGRA_AS_STRING(unsigned long long)
76 VIGRA_AS_STRING(signed int)
77 VIGRA_AS_STRING(unsigned int)
78 VIGRA_AS_STRING(float)
79 VIGRA_AS_STRING(double)
80 VIGRA_AS_STRING(long double)
81 VIGRA_AS_STRING(void *)
82 
83 #undef VIGRA_AS_STRING
84 
85 template <class T>
86 std::string operator<<(std::string const & s, T const & t)
87 {
88  std::stringstream ss;
89  ss << t;
90  return s + ss.str();
91 }
92 
93  /** Convert string to lower case.
94  */
95 inline std::string tolower(std::string s)
96 {
97  for(unsigned int k=0; k<s.size(); ++k)
98  s[k] = (std::string::value_type)std::tolower(s[k]);
99  return s;
100 }
101 
102 inline std::string tolower(const char * s)
103 {
104  return tolower(std::string(s));
105 }
106 
107  /** Convert string to lower case and remove any white space characters.
108  */
109 inline std::string normalizeString(std::string const & s)
110 {
111  std::string res;
112 
113  for(unsigned int k=0; k<s.size(); ++k)
114  {
115  if(std::isspace(s[k]))
116  continue;
117  res += (std::string::value_type)std::tolower(s[k]);
118  }
119  return res;
120 }
121 
122 inline std::string normalizeString(const char * s)
123 {
124  return normalizeString(std::string(s));
125 }
126 
127 namespace detail {
128 
129 template <class T>
130 struct FinallyImpl
131 {
132  T & destructor_;
133 
134  FinallyImpl(T & destructor)
135  : destructor_(destructor)
136  {}
137 
138  ~FinallyImpl()
139  {
140  destructor_();
141  }
142 };
143 
144 } // namespace detail
145 
146 } // namespace vigra
147 
148 #define VIGRA_TOKEN_PASTE_IMPL(x, y) x##y
149 #define VIGRA_TOKEN_PASTE(x, y) VIGRA_TOKEN_PASTE_IMPL(x, y)
150 
151 #define VIGRA_FINALLY_IMPL(destructor, counter) \
152  auto VIGRA_TOKEN_PASTE(_vigra_finally_impl_, counter) = [&]() { destructor; }; \
153  ::vigra::detail::FinallyImpl<decltype(VIGRA_TOKEN_PASTE(_vigra_finally_impl_, counter))> \
154  VIGRA_TOKEN_PASTE(_vigra_finally_, counter)(VIGRA_TOKEN_PASTE(_vigra_finally_impl_, counter))
155 
156  /** Emulate the 'finally' keyword as known from Python and other languages.
157 
158  This macro improves upon the famous
159  <a href="http://en.wikipedia.org/wiki/Resource_Acquisition_Is_Initialization">Resource Acquisition Is Initialization</a> idiom, where a resource (e.g. heap memory or a mutex) is automatically free'ed when program execution leaves the current scope. Normally, this is implemented by calling a suitable function in the destructor of a dedicated helper class (e.g. <tt>std::unique_ptr</tt> or <tt>std::lock_guard<std::mutex></tt>).
160 
161  Traditionally, a separate helper class has to be implemented for each kind of resource to be handled. In contrast, the macro <tt>VIGRA_FINALLY</tt> creates such a class on the fly by means of an embedded lambda expression.
162 
163  <b>Usage:</b>
164 
165  <b>\#include</b> <vigra/utilities.hxx><br/>
166 
167  \code
168  std::mutex my_mutex;
169  ...
170  {
171  // the following two lines are equivalent to
172  // std::unique_ptr<std::string> my_string = new std::string("foo");
173  std::string * my_string = new std::string("foo");
174  VIGRA_FINALLY(delete my_string);
175 
176  // the following two lines are equivalent to
177  // std::lock_guard<std::mutex> lock(my_mutex);
178  my_mutex.lock();
179  VIGRA_FINALLY(my_mutex.unlock());
180 
181  ...
182  }
183  // the string has been deallocated and the mutex is unlocked
184  \endcode
185 
186  You can pass any code to this macro. Multiple statements must be enclosed in braces as usual. Arbitrary many calls to <tt>VIGRA_FINALLY</tt> can be placed in the same scope. Their actions will be executed in the reversed order of declaration:
187 
188  \code
189  int i = 0;
190  ...
191  {
192  VIGRA_FINALLY({ // execute multiple statements
193  i = i*i;
194  ++i;
195  });
196 
197  VIGRA_FINALLY( i += 2 ); // this executes first
198 
199  assert(i == 0); // as yet, nothing happend
200  }
201  assert(i == 5); // 'finally' code was executed in reversed order at end-of-scope
202  \endcode
203 
204  This idea was popularized by Marko Tintor in "<a href="http://blog.memsql.com/c-error-handling-with-auto/">The Auto Macro: A Clean Approach to C++ Error Handling</a>".
205  */
206 #define VIGRA_FINALLY(destructor) \
207  VIGRA_FINALLY_IMPL(destructor, __COUNTER__)
208 
209 namespace std {
210 
211 template <class T1, class T2>
212 ostream & operator<<(ostream & s, std::pair<T1, T2> const & p)
213 {
214  s << "(" << p.first << ", " << p.second << ")";
215  return s;
216 }
217 
218 }
219 
220 /** \page Utilities Utilities
221  Basic helper functionality needed throughout.
222 
223  <UL style="list-style-image:url(documents/bullet.gif)">
224  <LI> \ref vigra::ArrayVector
225  <BR>&nbsp;&nbsp;&nbsp;<em>replacement for std::vector (always uses consecutive memory)</em>
226  <LI> \ref vigra::Any
227  <BR>&nbsp;&nbsp;&nbsp;<em>typesafe storage of arbitrary values</em>
228  <LI> \ref vigra::BucketQueue and \ref vigra::MappedBucketQueue
229  <BR>&nbsp;&nbsp;&nbsp;<em>efficient priority queues for integer priorities</em>
230  <LI> \ref RangesAndPoints
231  <BR>&nbsp;&nbsp;&nbsp;<em>2-D and N-D positions, extents, and boxes</em>
232  <LI> \ref PixelNeighborhood
233  <BR>&nbsp;&nbsp;&nbsp;<em>4- and 8-neighborhood definitions and circulators</em>
234  <LI> \ref VoxelNeighborhood
235  <BR>&nbsp;&nbsp;&nbsp;<em>6- and 26-neighborhood definitions and circulators</em>
236  <LI> \ref vigra::IteratorAdaptor
237  <BR>&nbsp;&nbsp;&nbsp;<em>Quickly create STL-compatible 1D iterator adaptors</em>
238  <LI> \ref TupleTypes
239  <BR>&nbsp;&nbsp;&nbsp;<em>pair, triple, tuple4, tuple5</em>
240  <LI> \ref MathConstants
241  <BR>&nbsp;&nbsp;&nbsp;<em>M_PI, M_SQRT2</em>
242  <LI> \ref TimingMacros
243  <BR>&nbsp;&nbsp;&nbsp;<em>Macros for taking execution speed measurements</em>
244  <LI> \ref VIGRA_FINALLY
245  <BR>&nbsp;&nbsp;&nbsp;<em>Emulation of the 'finally' keyword from Python</em>
246  </UL>
247 */
248 
249 #endif // VIGRA_BASICS_HXX
std::string tolower(std::string s)
Definition: utilities.hxx:95
Definition: array_vector.hxx:954
Definition: accessor.hxx:43
doxygen_overloaded_function(template<... > void separableConvolveBlockwise) template< unsigned int N
Separated convolution on ChunkedArrays.
std::string asString(T t)(...)
std::string normalizeString(std::string const &s)
Definition: utilities.hxx:109

© Ullrich Köthe (ullrich.koethe@iwr.uni-heidelberg.de)
Heidelberg Collaboratory for Image Processing, University of Heidelberg, Germany

html generated using doxygen and Python
vigra 1.10.0