long double to string

Question

I'm developping in C++, using the Qt framework.

I need to convert a long double value into a string (ideally a QString, but could be something else).

So far, I always used QString::number() for numerical->string conversion, but there is no overloading for the long doubletype.

Thanks

Answer 1

Simple:

string convert(long double myLongDouble) {
    stringstream blah;
    blah << myLongDouble;

    return blah.str();
}

With Templates:

template<class T> string convert(T _input) {
    stringstream blah;
    blah << _input;

    return blah.str();
}

Answer 2

Boost has lexical_cast for this purpose. It pretty much wraps the solution wheaties gave into a class template.

Answer 3

QString has a static function to construct a QString from a std::string, so wheaties' answer could be rewritten as:

#include <sstream>
#include <QString>
...
QString qStringFromLongDouble(const long double myLongDouble)
{
  std::stringstream ss;
  ss << myLongDouble;

  return QString::fromStdString(ss.str());
}