sigc::signal< T_return, T_arg1, T_arg2, T_arg3, T_arg4, T_arg5, T_arg6, T_arg7 >::accumulated< T_accumulator > Class Template Reference
[Signals]

Convenience wrapper for the numbered sigc::signal# templates. More...

Inherits sigc::signal7< T_return, T_arg1, T_arg2, T_arg3, T_arg4, T_arg5, T_arg6, T_arg7, T_accumulator >.

Collaboration diagram for sigc::signal< T_return, T_arg1, T_arg2, T_arg3, T_arg4, T_arg5, T_arg6, T_arg7 >::accumulated< T_accumulator >:
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Public Member Functions

 accumulated (const accumulated& src)

Detailed Description

template <class T_return, class T_arg1 = nil, class T_arg2 = nil, class T_arg3 = nil, class T_arg4 = nil, class T_arg5 = nil, class T_arg6 = nil, class T_arg7 = nil>
template <class T_accumulator>
class sigc::signal< T_return, T_arg1, T_arg2, T_arg3, T_arg4, T_arg5, T_arg6, T_arg7 >::accumulated< T_accumulator >

Convenience wrapper for the numbered sigc::signal# templates.

Like sigc::signal but the additional template parameter T_accumulator defines the accumulator type that should be used.

An accumulator is a functor that uses a pair of special iterators to step through a list of slots and calculate a return value from the results of the slot invokations. The iterators' operator*() executes the slot. The return value is buffered, so that in an expression like

 a = (*i) * (*i); 

the slot is executed only once. The accumulator must define its return value as result_type.

Example 1:
This accumulator calculates the arithmetic mean value:
 struct arithmetic_mean_accumulator
   {
     typedef double result_type;
     template<typename T_iterator>
     result_type operator()(T_iterator first, T_iterator last) const
 {
       result_type value_ = 0;
       int n_ = 0;
       for (; first != last; ++first, ++n_)
         value_ += *first;
       return value_ / n_;
     }
   };
Example 2:
This accumulator stops signal emission when a slot returns zero:
 struct interruptable_accumulator
   {
     typedef bool result_type;
     template<typename T_iterator>
     result_type operator()(T_iterator first, T_iterator last) const
 {
       for (; first != last; ++first, ++n_)
         if (!*first) return false;
       return true;
     }
   };

The documentation for this class was generated from the following file:

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