A traits class for a type stored in a boost::any. More...

Static Public Member Functions
static WString	asString (const Type &value, const WString &format)
	Converts a value to a string. More...

static double	asNumber (const Type &v)
	Converts a value to a number. More...

static int	compare (const Type &v1, const Type &v2)
	Compares two values. More...

Detailed Description

A traits class for a type stored in a boost::any.

The traits are used by Wt's view classes (such as Wt::WTableView Wt::WTreeView, Wt::Chart::WCartesianChart) to deal with values in a Wt::WAbstractItemModel:

This traits class provides a default implementation for supporting values value of a custom type Type in Wt's MVC system, which relies on:

serializing to a stream (std::ostream << value) for converting the value to a string.
lexical interpretation as a number for converting the value to a number, using boost::lexical_cast<double>(value).
sorting using operator== and operator<

You can specialize these traits if you need to customize one or more of these operations.

Member Function Documentation

template<typename Type >

double Wt::boost_any_traits< Type >::asNumber ( const Type & v )

static

Converts a value to a number.

The default implementation returns:

boost::lexical_cast<double>(asString(v), "")

template<typename Type >

WString Wt::boost_any_traits< Type >::asString	(	const Type &	value,
		const WString &	format
	)

static

Converts a value to a string.

The default implementation uses a boost::lexical_cast, and thus an overloaded std::ostream<< operator for the value.

template<typename Type >

int Wt::boost_any_traits< Type >::compare	(	const Type &	v1,
		const Type &	v2
	)

static

Compares two values.

The default implementation uses operator== and operator<.