Travis Vitek wrote:
>
>
>
> Ravi Inampudi-2 wrote:
>>
>> There is no template for "omanip" in C++ standard library.
>>
>
> I'm pretty sure that omanip was something from the old iostreams
> implementation. It is not in the standard.
>
>
> Ravi Inampudi-2 wrote:
>>
>> What are the options for people migrating to C++ standard library?
>>
>
> The option is to write out the code explicitly. The model would be
> something like this...
>
> #include <iostream>
>
> template <class CharT>
> struct repeat_n_impl {
> repeat_n_impl (CharT c, size_t n)
> : c_ (c), n_ (n)
> {
> }
>
> CharT c_;
> size_t n_;
> };
>
> template <class CharT, class TraitsT>
> std::basic_ostream<CharT, TraitsT>& operator<< (
> std::basic_ostream<CharT, TraitsT>& os,
> const repeat_n_impl<CharT>& rep)
> {
> for (size_t n = 0; n < rep.n_; ++n)
> os << rep.c_;
> return os;
> }
>
> template <class CharT>
> repeat_n_impl<CharT> repeat_n (CharT c, size_t n) {
> return repeat_n_impl<CharT>(c, n);
> }
>
> int main ()
> {
> std::cout << repeat_n ('a', 100) << std::endl;
> return 0;
> }
>
> Another option would be to implement something like the old omanip
> template. Unfortunately I only think that omanip worked for one additional
> parameter, so it wouldn't work with the above example. I believe that the
> following is similar...
>
> template <class T>
> struct omanip
> {
> typedef std::ostream& (*omanip_function)(std::ostream&, T);
>
> omanip (omanip_function fn, T val)
> : fn_ (fn), val_ (val)
> {
> }
>
> friend std::ostream& operator<< (std::ostream& os, const omanip&
> om)
> {
> return om.fn_ (os, om.val_);
> }
>
> omanip_function fn_;
> T val_;
> };
>
> Travis
>
Another disadvantage of this is that it doesn't work with other stream
types. I.e. it doesn't work with std::wostream. You could make some
modifications, but the syntax that the user would need to write would
change.
Travis
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