Function main

samples/xmpsample.cpp:15–206

}

int main() try {
  Exiv2::XmpParser::initialize();
  ::atexit(Exiv2::XmpParser::terminate);

  // The XMP property container
  Exiv2::XmpData xmpData;

  // -------------------------------------------------------------------------
  // Teaser: Setting XMP properties doesn't get much easier than this:

  xmpData["Xmp.dc.source"] = "xmpsample.cpp";  // a simple text value
  xmpData["Xmp.dc.subject"] = "Palmtree";      // an array item
  xmpData["Xmp.dc.subject"] = "Rubbertree";    // add a 2nd array item
  // a language alternative with two entries and without default
  xmpData["Xmp.dc.title"] = "lang=de-DE Sonnenuntergang am Strand";
  xmpData["Xmp.dc.title"] = "lang=en-US Sunset on the beach";

  // -------------------------------------------------------------------------
  // Any properties can be set provided the namespace is known. Values of any
  // type can be assigned to an Xmpdatum, if they have an output operator. The
  // default XMP value type for unknown properties is a simple text value.

  xmpData["Xmp.dc.one"] = -1;
  xmpData["Xmp.dc.two"] = 3.1415;
  xmpData["Xmp.dc.three"] = Exiv2::Rational(5, 7);
  xmpData["Xmp.dc.four"] = static_cast<uint16_t>(255);
  xmpData["Xmp.dc.five"] = 256;
  xmpData["Xmp.dc.six"] = false;

  // In addition, there is a dedicated assignment operator for Exiv2::Value
  Exiv2::XmpTextValue val("Seven");
  xmpData["Xmp.dc.seven"] = val;
  xmpData["Xmp.dc.eight"] = true;

  // Extracting values
  assert(xmpData["Xmp.dc.one"].toInt64() == -1);
  assert(xmpData["Xmp.dc.one"].value().ok());

  [[maybe_unused]] const Exiv2::Value& getv1 = xmpData["Xmp.dc.one"].value();
  assert(isEqual(getv1.toFloat(), -1));
  assert(getv1.ok());
  assert(getv1.toRational() == Exiv2::Rational(-1, 1));
  assert(getv1.ok());

  [[maybe_unused]] const Exiv2::Value& getv2 = xmpData["Xmp.dc.two"].value();
  assert(isEqual(getv2.toFloat(), 3.1415f));
  assert(getv2.ok());
  assert(getv2.toInt64() == 3);
  assert(getv2.ok());
  [[maybe_unused]] Exiv2::Rational R = getv2.toRational();
  assert(getv2.ok());
  assert(isEqual(static_cast<float>(R.first) / R.second, 3.1415f));

  [[maybe_unused]] const Exiv2::Value& getv3 = xmpData["Xmp.dc.three"].value();
  assert(isEqual(getv3.toFloat(), 5.0f / 7.0f));
  assert(getv3.ok());
  assert(getv3.toInt64() == 0);  // long(5.0 / 7.0)
  assert(getv3.ok());