Converting sprintf to ostringstream

[jasonwthompson]

I'm converting some old C code to C++. Although I'm not concerned
about converting every C item to C++ I'm in a situation in which using
an ostringstream makes more sense than using sprintf. Here's my
problem: In sprintf, one could use the %g symbol to indicate that I
either wanted scientific notation or a simple floating point,
whichever is smaller. Is there a way to do that using an
ostringstream?

Basically, what is the ostringstream equivalent of:

sprintf(buffer, "%-20.12g",mynum);

 

[Victor Bazarov]

I'm converting some old C code to C++. Although I'm not concerned
about converting every C item to C++ I'm in a situation in which using
an ostringstream makes more sense than using sprintf. Here's my
problem: In sprintf, one could use the %g symbol to indicate that I
either wanted scientific notation or a simple floating point,
whichever is smaller. Is there a way to do that using an
ostringstream?

Basically, what is the ostringstream equivalent of:

sprintf(buffer, "%-20.12g",mynum);

I would think it does that by default, no? Just output 'mynum' and
it should do what you need. As to '20' and '12', look for the 'setw'
and 'setprecision' manipulators.

V

 

[jasonwthompson]

Ah... I see. I was trying too hard. Yes it does do it like the %g
by default. Thanks!