coco
293 lines
9.0 KiB
C++
293 lines
9.0 KiB
C++
// Copyright (C) 2011 Davis E. King (davis@dlib.net)
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// License: Boost Software License See LICENSE.txt for the full license.
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#undef DLIB_AnY_FUNCTION_ABSTRACT_H_
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#ifdef DLIB_AnY_FUNCTION_ABSTRACT_H_
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#include "any_abstract.h"
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#include "../algs.h"
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namespace dlib
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{
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// ----------------------------------------------------------------------------------------
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template <
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typename function_type
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>
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class any_function
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{
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/*!
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REQUIREMENTS ON function_type
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This type should be a function signature. Some examples are:
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void (int,int) // a function returning nothing and taking two ints
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void () // a function returning nothing and taking no arguments
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char (double&) // a function returning a char and taking a reference to a double
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The number of arguments in the function must be no greater than 10.
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INITIAL VALUE
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- is_empty() == true
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- for all T: contains<T>() == false
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WHAT THIS OBJECT REPRESENTS
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This object is a version of dlib::any that is restricted to containing
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elements which are some kind of function object with an operator() which
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matches the function signature defined by function_type.
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Here is an example:
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#include <iostream>
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#include <string>
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#include "dlib/any.h"
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using namespace std;
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void print_message(string str) { cout << str << endl; }
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int main()
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{
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dlib::any_function<void(string)> f;
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f = print_message;
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f("hello world"); // calls print_message("hello world")
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}
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Note that any_function objects can be used to store general function
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objects (i.e. defined by a class with an overloaded operator()) in
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addition to regular global functions.
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!*/
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public:
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// This is the type of object returned by function_type functions.
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typedef result_type_for_function_type result_type;
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// Typedefs defining the argument types. If an argument does not exist
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// then it is set to void.
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typedef type_of_first_argument_in_funct_type arg1_type;
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typedef type_of_second_argument_in_funct_type arg2_type;
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...
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typedef type_of_last_argument_in_funct_type arg10_type;
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const static unsigned long num_args = total_number_of_non_void_arguments;
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any_function(
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);
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/*!
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ensures
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- this object is properly initialized
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!*/
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any_function (
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const any_function& item
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);
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/*!
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ensures
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- copies the state of item into *this.
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- Note that *this and item will contain independent copies of the
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contents of item. That is, this function performs a deep
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copy and therefore does not result in *this containing
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any kind of reference to item.
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!*/
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template < typename T >
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any_function (
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const T& item
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);
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/*!
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ensures
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- #contains<T>() == true
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- #cast_to<T>() == item
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(i.e. a copy of item will be stored in *this)
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!*/
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void clear (
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);
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/*!
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ensures
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- #*this will have its default value. I.e. #is_empty() == true
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!*/
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template <typename T>
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bool contains (
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) const;
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/*!
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ensures
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- if (this object currently contains an object of type T) then
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- returns true
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- else
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- returns false
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!*/
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bool is_empty(
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) const;
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/*!
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ensures
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- if (this object contains any kind of object) then
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- returns false
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- else
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- returns true
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!*/
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bool is_set (
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) const;
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/*!
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ensures
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- returns !is_empty()
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!*/
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result_type operator() (
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) const;
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/*!
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requires
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- is_empty() == false
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- the signature defined by function_type takes no arguments
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ensures
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- Let F denote the function object contained within *this. Then
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this function performs:
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return F()
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or if result_type is void then this function performs:
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F()
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!*/
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result_type operator() (
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const arg1_type& a1
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) const;
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/*!
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requires
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- is_empty() == false
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- the signature defined by function_type takes one argument
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ensures
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- Let F denote the function object contained within *this. Then
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this function performs:
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return F(a1)
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or if result_type is void then this function performs:
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F(a1)
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!*/
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result_type operator() (
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const arg1_type& a1,
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const arg2_type& a2
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) const;
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/*!
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requires
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- is_empty() == false
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- the signature defined by function_type takes two arguments
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ensures
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- Let F denote the function object contained within *this. Then
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this function performs:
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return F(a1,a2)
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or if result_type is void then this function performs:
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F(a1,a2)
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!*/
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/* !!!!!!!!! NOTE !!!!!!!!!
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In addition to the above, operator() is defined for up to 10 arguments.
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They are not listed here because it would clutter the documentation.
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!!!!!!!!! NOTE !!!!!!!!! */
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template <typename T>
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T& cast_to(
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);
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/*!
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ensures
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- if (contains<T>() == true) then
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- returns a non-const reference to the object contained within *this
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- else
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- throws bad_any_cast
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!*/
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template <typename T>
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const T& cast_to(
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) const;
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/*!
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ensures
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- if (contains<T>() == true) then
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- returns a const reference to the object contained within *this
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- else
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- throws bad_any_cast
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!*/
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template <typename T>
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T& get(
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);
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/*!
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ensures
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- #is_empty() == false
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- #contains<T>() == true
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- if (contains<T>() == true)
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- returns a non-const reference to the object contained in *this.
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- else
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- Constructs an object of type T inside *this
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- Any previous object stored in this any_function object is destructed and its
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state is lost.
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- returns a non-const reference to the newly created T object.
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!*/
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any_function& operator= (
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const any_function& item
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);
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/*!
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ensures
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- copies the state of item into *this.
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- Note that *this and item will contain independent copies of the
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contents of item. That is, this function performs a deep
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copy and therefore does not result in *this containing
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any kind of reference to item.
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!*/
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void swap (
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any_function& item
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);
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/*!
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ensures
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- swaps *this and item
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!*/
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};
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// ----------------------------------------------------------------------------------------
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template <
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typename function_type
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>
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inline void swap (
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any_function<function_type>& a,
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any_function<function_type>& b
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) { a.swap(b); }
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/*!
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provides a global swap function
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!*/
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// ----------------------------------------------------------------------------------------
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template <
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typename T,
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typename function_type
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>
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T& any_cast(
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any_function<function_type>& a
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) { return a.cast_to<T>(); }
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/*!
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ensures
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- returns a.cast_to<T>()
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!*/
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// ----------------------------------------------------------------------------------------
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template <
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typename T,
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typename function_type
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>
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const T& any_cast(
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const any_function<function_type>& a
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) { return a.cast_to<T>(); }
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/*!
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ensures
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- returns a.cast_to<T>()
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!*/
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// ----------------------------------------------------------------------------------------
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}
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#endif // DLIB_AnY_FUNCTION_ABSTRACT_H_
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