XtConvert(), XtDirectConvert() - invoke resource converters
void XtConvert (Widget w, String from_type, XrmValuePtr from,
String to_type, XrmValuePtr to_return)
void XtDirectConvert (XtConverter converter, XrmValuePtr args,
Cardinal num_args, XrmValuePtr from,
XrmValuePtr to_return)
The XtConvert(3) function looks up the type converter registered to convert from_type to to_type, computes any additional arguments needed, and then calls XtDirectConvert(3).
The XtDirectConvert(3) function looks in the converter cache to see if this conversion procedure has been called with the specified arguments. If so, it returns a descriptor for information stored in the cache; otherwise, it calls the converter and enters the result in the cache.
Before calling the specified converter, XtDirectConvert(3) sets the return value size to zero and the return value address to NULL. To determine if the conversion was successful, the client should check to_return.address for non-NULL.
X Toolkit Intrinsics - C Language Interface
Xlib - C Language X Interface