The default value of an option, and
the value of a combining numeric option,
gets inserted directly into the generated code without any further
interpolation, as is. It can be a constant, a preprocessor symbol, or an
expression:
<default>5</default> <!-- ... --> <default>BUFSIZE+3</default>
String values must use quotes.
<option> <name>reportname</name> <type>string</type> <opt>n</opt> <longopt>name</longopt> <descr>Report's name</descr> <hasvalue /> <default>"global"</default> <argdescr>name</argdescr> </option>
Default class values typically require the use of a constructor call.
<option> <name>nodekey_expire</name> <type>ymd_interval</type> <opt>e</opt> <longopt>expires</longopt> <descr>Key's expiration</descr> <hasvalue /> <argdescr>interval</argdescr> <default>x::ymd::interval("1 year")</default> </option>