Thus, instead of ‘--option <name> <value>’, you can write ‘--<name>
<value>’. So
--option http-connections 100
becomes
--http-connections 100
Apart from brevity, the difference is that it's not an error to set a
non-existent option via --option, but unrecognized arguments are
fatal.
Boolean options have special treatment: they're mapped to the
argument-less flags ‘--<name>’ and ‘--no-<name>’. E.g.
--option auto-optimise-store false
becomes
--no-auto-optimise-store
The typical use is to inherit Config and add Setting<T> members:
class MyClass : private Config
{
Setting<int> foo{this, 123, "foo", "the number of foos to use"};
Setting<std::string> bar{this, "blabla", "bar", "the name of the bar"};
MyClass() : Config(readConfigFile("/etc/my-app.conf"))
{
std::cout << foo << "\n"; // will print 123 unless overriden
}
};
Currently, this is used by Store and its subclasses for store
parameters. You now get a warning if you specify a non-existant store
parameter in a store URI.