"Nick Hounsome" <nh002@blueyonder.co.uk> wrote in message
news:Hy5Nb.604$M26.453@news-binary.blueyonder.co.uk...

"David Harmon" <source@netcom.com> wrote in message
news:4018cb98.33199246@news.west.earthlink.net...

On 13 Jan 2004 19:40:25 -0800 in comp.lang.c++,

I 've decided it's time to move from fortran to c++, but i cant find
out if c++ supposrts I/O format commands like the ones in fortran 77.

The printf(), scanf(), etc. library functions, that C++ inherits
from C, provide formatted I/O somewhat reminiscent of Fortran

I/O. Most C++ programmers prefer the standard iostreams library for
type safety and extensibility.

Do they really?

I think it depends on what you mean by formatted. Personally I find them
extremely clunky for doing what I usualy think of
as formatted I/O i.e. the difference between 0x%06x and %d.

Putting aside the biggest problem which is properly saving and restoring

the

base and fill character, including iomanip,
upper versus lower case hex letters and the std namespace you still

cout << x << hex << "0x" << setw(6) << setfill('0') << y << dec;
versus
printf("%d 0x%06x",x,y);

I think that the standard should actualy supply a class to save and

restore

all this 'stuff' automatically in ctor/dtor e.g.
std::format_state fs(cout);

See http://www.boost.org/libs/io/doc/ios_state.html which saves the state

you desire. If you still insist on printf, see
http://www.boost.org/libs/format/index.htm for a typesafe version.

Jeff F

I 've decided it's time to move from fortran to c++, but i cant find
out if c++ supposrts I/O format commands like the ones in fortran 77.

The printf(), scanf(), etc. library functions, that C++ inherits
from C, provide formatted I/O somewhat reminiscent of Fortran

I/O. Most C++ programmers prefer the standard iostreams library for
type safety and extensibility.

Personally I find them extremely clunky

cout << x << hex << "0x" << setw(6) << setfill('0') << y << dec;

Or, if you follow the advice of some, it's even worse:
std::cout << x << std::hex << "0x" << std::setw(6)
<< std::setfill('0') << y << std::dec;

versus
printf("%d 0x%06x",x,y);

This is perfectly good and correct C++, nobody is forcing you to

use iostreams. If you want to avoid memory-allocation with sprintf
in general, write a small function that uses vsnprintf() to put the
output in a std::string instead of a char* . If you want type-safety,

I 've decided it's time to move from fortran to c++, but i cant find
out if c++ supposrts I/O format commands like the ones in fortran 77.

The printf(), scanf(), etc. library functions, that C++ inherits
from C, provide formatted I/O somewhat reminiscent of Fortran formatted
I/O. Most C++ programmers prefer the standard iostreams library for
type safety and extensibility.

Personally I find them extremely clunky

cout << x << hex << "0x" << setw(6) << setfill('0') << y << dec;

Or, if you follow the advice of some, it's even worse:
std::cout << x << std::hex << "0x" << std::setw(6)
<< std::setfill('0') << y << std::dec;

versus
printf("%d 0x%06x",x,y);

This is perfectly good and correct C++, nobody is forcing you to
use iostreams. If you want to avoid memory-allocation with sprintf
in general, write a small function that uses vsnprintf() to put the
output in a std::string instead of a char* . If you want type-safety,
use boost::format (although I avoid this because it slows down the
build a lot, without precompiled headers).

This is perfectly good and correct C++, nobody is forcing you to
use iostreams. If you want to avoid memory-allocation with sprintf
in general, write a small function that uses vsnprintf() to put the
output in a std::string instead of a char* .

Nick Hounsome wrote in
news:Hy5Nb.604$M26.453@news-binary.blueyonder.co.uk:

I think that the standard should actualy supply a class to save and
restore all this 'stuff' automatically in ctor/dtor e.g.
std::format_state fs(cout);

void f( int i )
{
std::ostream os( cout.rdbuf() );
os << std::hex << i;
}

Rob.
--
http://www.victim-prime.dsl.pipex.com/