Where is va_args now?

In my program I often need to use parameters to create log messages and to create string commands. For example:

Code:

printf("Time of event %s:\nEvent: %s\n", event_time, description);

This is not real code, but illustrate what I mean. I had to create an exception class that allows me to create error messages with parameters in a straightforward manner, using va_args. This is the constructor:

Code:

Excecao::Excecao(const char* fmt, ...)
{
		va_list listaParam;
		va_start(listaParam, fmt);

		setStr(fmt, listaParam);

		va_end(listaParam);
}

void Excecao::setStr(const char* fmt, va_list args)
{
		char buffer[1024];
		vsnprintf(buffer, 1024, fmt, args);

		_description = buffer;
}

The code is not perfect, I know. I do not know how to do it better. However, the point is: is this kind of construction possible in C++? I was changing char* to string, now I can't use sprintf to format my command in one line.

Thanks any suggestion or comment.

In C++-style, you'd probably use stringstreams for that sort of thing. Check out the FAQ.

It is possible to use <cstdargs>, sprintf(), and any C function in C++, it's just not recommended.

I don't know cstdargs, I will take a look, thanks!

It's C's <stdarg.h> in C++. And I meant <cstdarg>. You know it, you're using it.

[edit] Check out http://faq.cprogramming.com/cgi-bin/...&id=1043284385 [/edit]

If all the arguments are strings, you don't need sprintf or stringstreams. Just add the strings together with + or +=.