[RFA] Algorithms vs operator* and operator==

[Paolo Carlini]

chris jefferson wrote:

> Therefore, similarily I have 3 options..
>
> 1) Make the int, float, etc. case efficent
> 2) Make the vector, list, etc case efficent
> 3) Use somethiing like _is_scalar (and perhaps others.. is_pod comes 
> to mind)  to try to decide when to make the choice
>
> Any opinions? :)

I would suggest 3) :)

By the way, this is a preliminary list of algorithms taking 
input_iterators, first candidates for the optimization that I presented 
at the outset:

replace_copy
replace_copy_if
remove_copy
remove_copy_if
unique_copy
partial_sort_copy
merge
includes
set_*
find_first_of
lexicographical_compare (+, unrelated, specialization for wchar_t?)

Some are "more" candidates than others, either because are very simple - 
sparing operator* calls can make for a big difference - or because don't 
have already sets of overloaded helpers (-> the total number of 
templates would grow very large affecting badly /compile time/ 
performance! We never discussed this issue in detail, by the way...)

Paolo.