IValue< nam, cnst, T > Struct Template Reference

A leaf that holds a value. More...

#include "IOption.hpp"

Inheritance diagram for IValue< nam, cnst, T >:

Public Types
using	Name = NameT< nam >
using	Node = NodeT< Nodes::value >

Public Member Functions
virtual UsageLevel	usageLevel () const =0
	Frequency / expected skills of users that access this leaf.
virtual ValueSource	valueSource () const =0
	The context in which the value has been set.
virtual bool	empty () const =0
	If its value has not been set, a leaf is considered empty. More...
virtual	operator bool () const =0
	Returns !empty()
virtual const T &	get () const =0
	Get the value.
virtual T	getOr (T &&default_) const =0
	Get the value or default_ if empty.
virtual const T &	getOr (const T &default_) const =0
Public Member Functions inherited from IBase
virtual Names	enumerator () const =0
	The option name as enumerator.
virtual String	name () const =0
	The option name as string.
virtual String	path () const =0
	The option name as string, preceded by the names of its parents, if any, interspersed with '.'.
virtual String	shortDescription () const =0
	One-liner that describes this option.
virtual String	longDescription () const =0
	Longer text that describes this option in more detail.
virtual UsageLevel	minUsageLevel () const =0
	For a leaf, this is its own usage level. Otherwise, this is the minimum usage level of all descendants: basic < mid < pro.
virtual Nodes	node () const =0
	The node type of this option.

Detailed Description

template<Names nam, bool cnst, class T>
struct opals::opts::IValue< nam, cnst, T >

A leaf that holds a value.

Template Parameters

nam	The value name.
cnst	If true, then the value may not be changed.
T	The value type.

Member Function Documentation

empty()

virtual bool empty ( ) const

pure virtual

If its value has not been set, a leaf is considered empty.

Accessing its value then raises an exception.