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Groups > comp.lang.c++ > #9061

Re: concatenate variable number of arguments and types to a char *

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On 19.08.2011 06:04, suresh wrote:
> Hi
> How to write a function which would concatenate variable number of arguments of
> different  type and return a char *. For example I need the function
>
> f("his weight is = ", 51.5, "pounds");
>
> to return the string "his weight is =  51.5 pounds".

One simple way is like (off the cuff)

   template< class T >
   string toString( T const& v )
   {
       stringstream stream_;
       stream_ << v;
       return stream.str();
   }

   struct S
   {
       string  s_;
   public:
       template< class T >
       S& operator<<( T const& v )
       {
           s_ += toString( v );
           return *this;
       }

       operator char const* () const
       {
           return s_.c_str();
       }
   };

It can be elaborated and, not the least, optimized.

Anyway, then, when you want to call a function

   void foo( char const* s )

you can say things like

   foo( S() << "his weight is = " << 51.5 << "pounds" )

Cheers & hth.,

- Alf

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Thread

concatenate variable number of arguments and types to a char * suresh <suresh.amritapuri@gmail.com> - 2011-08-18 21:04 -0700
  Re: concatenate variable number of arguments and types to a char * "Alf P. Steinbach" <alf.p.steinbach:usenet@gmail.com> - 2011-08-19 06:26 +0200
  Re: concatenate variable number of arguments and types to a char * Felix Bytow <felix.bytow@informatik.tu-chemnitz.de> - 2011-08-19 06:50 +0200
    Re: concatenate variable number of arguments and types to a char * "Alf P. Steinbach" <alf.p.steinbach:usenet@gmail.com> - 2011-08-19 08:04 +0200
  Re: concatenate variable number of arguments and types to a char * PaulR <pchristor@yahoo.co.uk> - 2011-08-19 04:01 -0700
    Re: concatenate variable number of arguments and types to a char * Leigh Johnston <leigh@i42.co.uk> - 2011-08-19 14:00 +0100
      Re: concatenate variable number of arguments and types to a char * Juha Nieminen <nospam@thanks.invalid> - 2011-08-19 14:31 +0000
        Re: concatenate variable number of arguments and types to a char * "Alf P. Steinbach" <alf.p.steinbach:usenet@gmail.com> - 2011-08-19 16:57 +0200
          Re: concatenate variable number of arguments and types to a char * Juha Nieminen <nospam@thanks.invalid> - 2011-08-19 19:15 +0000
        Re: concatenate variable number of arguments and types to a char * Leigh Johnston <leigh@i42.co.uk> - 2011-08-19 16:33 +0100
          Re: concatenate variable number of arguments and types to a char * Juha Nieminen <nospam@thanks.invalid> - 2011-08-19 19:18 +0000
            Re: concatenate variable number of arguments and types to a char * Leigh Johnston <leigh@i42.co.uk> - 2011-08-19 20:29 +0100
              Re: concatenate variable number of arguments and types to a char * Paul <pchristor@yahoo.co.uk> - 2011-08-19 14:18 -0700
                Re: concatenate variable number of arguments and types to a char * Leigh Johnston <leigh@i42.co.uk> - 2011-08-19 22:37 +0100
                Re: concatenate variable number of arguments and types to a char   * Ian Collins <ian-news@hotmail.com> - 2011-08-20 09:43 +1200
                Re: concatenate variable number of arguments and types to a char * Paul <pchristor@yahoo.co.uk> - 2011-08-19 15:08 -0700
            Re: concatenate variable number of arguments and types to a char * Victor Bazarov <v.bazarov@comcast.invalid> - 2011-08-19 16:14 -0400
              Re: concatenate variable number of arguments and types to a char * Paul <pchristor@yahoo.co.uk> - 2011-08-19 13:54 -0700
                Re: concatenate variable number of arguments and types to a char * Leigh Johnston <leigh@i42.co.uk> - 2011-08-19 22:01 +0100
                Re: concatenate variable number of arguments and types to a char * Paul <pchristor@yahoo.co.uk> - 2011-08-19 14:20 -0700
                Re: concatenate variable number of arguments and types to a char * Paul <pchristor@yahoo.co.uk> - 2011-08-19 14:21 -0700
      Re: concatenate variable number of arguments and types to a char * Paul <pchristor@yahoo.co.uk> - 2011-08-19 11:03 -0700
        Re: concatenate variable number of arguments and types to a char * Leigh Johnston <leigh@i42.co.uk> - 2011-08-19 19:23 +0100
      Re: concatenate variable number of arguments and types to a char * red floyd <no.spam.here@its.invalid> - 2011-08-19 11:13 -0700
        Re: concatenate variable number of arguments and types to a char * Leigh Johnston <leigh@i42.co.uk> - 2011-08-19 19:39 +0100

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