c++ equivalent function to the c-function 'sprintf

Hi

Is there a c++ equivalent function to the c-function 'sprintf'?

Thnaks

You can also check out boost::format, which can be easier to work with than stringstream

thank you, that looks much more convenient!

I guess it's rather ::sprintf (with extern "C" { / #include <stdio.h> / }).

But if you want some safety, you'd use ::snprintf, and if you don't want to implement the safety yourself, you could rather use lisp^W std:stringstream.

std:stringstream s; s<<"Hi "<<world<<std::endl;
std::string str =s.str();
const char* cstr=s.c_str();

C functions are in the "root" namespace; to avoid
refering a different object in the current namespace, it's advised (in various style guides) to qualify C functions.

Then, using a function without declaring it would make a sane compiler complain, so it's good practice to include some header declaring it before using it.

The is the C++ group here, so the C header <stdio.h> is to be
included using <cstdio> and its content is accessible only within
the 'std' namespace.

This is works well, works like a sprintf for c++

Code:

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std::string string_format(const std::string &fmt, ...) {
      int n, size=100;
      std::string str;
      va_list ap;
      while (1) {
      str.resize(size);
      va_start(ap, fmt);
      int n = vsnprintf((char *)str.c_str(), size, fmt.c_str(), ap);
      va_end(ap);
      if (n > -1 && n < size)
          return str;
      if (n > -1)
          size=n+1;
      else
          size*=2;
      }
}

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