libzypp  17.23.5
Function.h
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12 #ifndef ZYPP_BASE_FUNCTION_H
13 #define ZYPP_BASE_FUNCTION_H
14 
15 #include <boost/function.hpp>
16 #include <boost/bind.hpp>
17 #include <boost/ref.hpp>
18 
20 namespace zypp
21 {
22 
23  /* http://www.boost.org/doc/html/function.html
24 
25  The Boost.Function library contains a family of class templates
26  that are function object wrappers. The notion is similar to a
27  generalized callback. It shares features with function pointers
28  in that both define a call interface (e.g., a function taking
29  two integer arguments and returning a floating-point value)
30  through which some implementation can be called, and the
31  implementation that is invoked may change throughout the
32  course of the program.
33 
34  Generally, any place in which a function pointer would be used
35  to defer a call or make a callback, Boost.Function can be used
36  instead to allow the user greater flexibility in the implementation
37  of the target. Targets can be any 'compatible' function object
38  (or function pointer), meaning that the arguments to the interface
39  designated by Boost.Function can be converted to the arguments of
40  the target function object.
41  */
42  using boost::function;
43 
44  /* http://www.boost.org/libs/bind/bind.html
45 
46  boost::bind is a generalization of the standard functions std::bind1st
47  and std::bind2nd. It supports arbitrary function objects, functions,
48  function pointers, and member function pointers, and is able to bind
49  any argument to a specific value or route input arguments into arbitrary
50  positions. bind does not place any requirements on the function object;
51  in particular, it does not need the result_type, first_argument_type and
52  second_argument_type standard typedefs.
53  */
54  using boost::bind;
55 
56  /* http://www.boost.org/doc/html/ref.html
57 
58  The Ref library is a small library that is useful for passing references
59  to function templates (algorithms) that would usually take copies of their
60  arguments. It defines the class template boost::reference_wrapper<T>, the
61  two functions boost::ref and boost::cref that return instances of
62  boost::reference_wrapper<T>, and the two traits classes
63  boost::is_reference_wrapper<T> and boost::unwrap_reference<T>.
64 
65  The purpose of boost::reference_wrapper<T> is to contain a reference to an
66  object of type T. It is primarily used to "feed" references to function
67  templates (algorithms) that take their parameter by value.
68 
69  To support this usage, boost::reference_wrapper<T> provides an implicit
70  conversion to T&. This usually allows the function templates to work on
71  references unmodified.
72  */
73  using boost::ref;
74 
76 } // namespace zypp
78 #endif // ZYPP_BASE_FUNCTION_H
zypp
Easy-to use interface to the ZYPP dependency resolver.
Definition: CodePitfalls.doc:1