Re: best efficient and readable way to concatenate strings (or the best trade-offs)

From:
 Diego Martins <jose.diego@gmail.com>
Newsgroups:
comp.lang.c++
Date:
Tue, 19 Jun 2007 14:27:11 -0000
Message-ID:
<1182263231.351371.233980@q75g2000hsh.googlegroups.com>
On Jun 18, 6:18 pm, Alan Johnson <a...@yahoo.com> wrote:

I'm a fan of the following syntax for operations that can take an
indefinite number of parameters:

[snip]

int main()
{
     int n = 4 ;
     float x = .99 ;
     std::string test = concat("We bought ")(n)(" items at ")(x)("
price").str() ;
     std::cout << test << std::endl ;
}


thanks for all responses. the above approach is very nice. I liked the
boost::format too (seems to be very powerful)

I believe the syntax above could be improved to something like this:
std::string test = concat("we bought") + n + " items at " + x + "
price";

concat class must have a templated operator+() as a member function
template<typename T>
concat & concat::operator+(T value) { stream << value; return *this; }

and an operator string to retrieve/compute the result
string concat::operator string(); { return stream.str(); }

if optimization is an issue, we might find a way to use a vector of
pointers (and typeinfos? o__O) to concat all members at a time in the
operator string (a custom concatenation? a reserve and vector of
chars? it could be trickier than one can imagine..)

more ideas?
Diego

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