Thread: for_each function and operator()

Hello everyone,


I can not find related information in MSDN, so I want to confirm here, that,

the implementation of for_each is something like,

Code:

template <class A, class B> B for_each (A begin, A end, B Func)
{
    while (begin != end) Func(*begin++);
    return Func;
}

So, operator(*A) of class Func will be invoked? Right?


thanks in advance,
George

the implementation of for_each is something like

The C++ Standard declares std::for_each() as:

Code:

template<class InputIterator, class Function>
Function for_each(InputIterator first, InputIterator last, Function f);

The MinGW port of g++ 3.4.5 has an implementation that amounts to:

Code:

template<class InputIterator, class Function>
Function for_each(InputIterator first, InputIterator last, Function f)
{
    for (; first != last; ++first)
    {
        f(*first);
    }
    return f;
}

So, operator(*A) of class Func will be invoked? Right?

Function::operator(InputIterator::value_type) is the overloaded operator that will be invoked.

I seems to me that Func doesn't necessarily have to be a function object but might be a simple function with a suitable prototype.

I seems to me that Func doesn't necessarily have to be a function object but might be a simple function with a suitable prototype.

Yes, that is true.