Exceptional coding style

[Mehrdad]

On Wednesday, 16 January 2013 at 18:38:21 UTC, Mehrdad wrote:
> On Wednesday, 16 January 2013 at 11:00:48 UTC, mist wrote:
>>> When you have a ton of similar lines of code which need to be 
>>> edited in parallel, lining them up lets you edit all of them 
>>> in one keystroke. Saves me quite a lot of annoying editing in 
>>> the long run, actually.
>>
>> When you have a ton of similar lines of code, you'd better 
>> start thinking about templates or mixins :P
>
>
> Easy to say in theory, but makes absolutely no sense in many 
> cases. =P
>
> Example:
> boost::unordered_set<int> foo;
> boost::unordered_map<int> bar;
>
>
> and now I want to change 'boost' to 'std' because C++11 came 
> out.
>
> Templates? Mixins? wtf lol

Another example:

template<class T> struct foo
{
	int x;
	int operator+(int) const { }
	int operator-(int) const { }
	int operator*(int) const { }
};

template<class T> int foo<T>::operator+(int x) const { return 
this->x + x; }
template<class T> int foo<T>::operator-(int x) const { return 
this->x - x; }
template<class T> int foo<T>::operator*(int x) const { return 
this->x * x; }



let's say now I want to add a new template parameter, class U, to 
all the functions.



If you can teach me how "templates" or "mixins" would solve my 
problem here I'd love to know.