Any Class Reference

Typesafe storage of arbitrary values. More...

#include <vigra/any.hxx>

Public Member Functions
	Any ()
template<class T >
	Any (T const &t)
	Any (Any const &other)
void	destroy ()
bool	empty () const
template<class T >
T &	get ()
template<class T >
T const &	get () const
template<class T >
bool	is_readable () const
template<class T >
bool	is_type () const
	operator bool () const
bool	operator!= (Any const &other) const
template<class T >
Any &	operator= (T const &t)
Any &	operator= (Any const &other)
bool	operator== (Any const &other) const
template<class T >
T	read () const
void	swap (Any &other)

Friends
void	swap (Any &l, Any &r)

Detailed Description

Typesafe storage of arbitrary values.

Items are always stored by value, but it is of course possible to store pointers and smart pointers.

Usage:

Any a(10);  // store integer '10'

assert(a.is_type<int>());
assert(a.is_convertible<int>());

// retrieve the stored value (throws when types don't match)
assert(a.get<int>() == 10);

// change the value
a = 20;
assert(a.get<int>() == 20);

// values of arithmetic types can be converted into each other
// (this is currently not implemented for other types)
assert(a.is_convewrtible<double>());
assert(a.cast<double>() == 20.0);

// delete the stored value
a.destroy();
assert(a.empty());
assert(a == false);

// store a shared_ptr
typedef std::shared_ptr<int> Ptr;
Any p(Ptr(new int(5))), q = p;
assert(*(p.get<Ptr>()) == 5);
// the addresses of the elements in p and q are the same
assert(p.get<Ptr>().get() == p.get<Ptr>().get());

Constructor & Destructor Documentation

Any

(

)

Construct empty 'Any' object.

Any

(

T const &

t

)

Construct 'Any' object holding the given value.

Any

(

Any const &

other

)

Construct 'Any' object holding a copy of other's value.

Member Function Documentation

Any& operator=

(

T const &

t

)

Assign the given value to this 'Any' object (overwrites the old value, regardless of types).

Any& operator=

(

Any const &

other

)

Assign a copy of other's value to this 'Any' object (overwrites the old value, regardless of types).

void destroy

(

)

Delete the contained object (make this 'Any' object empty).

void swap

(

Any &

other

)

Exchange the value of this object with other's.

bool operator==

(

Any const &

other

)

const

Check if this object contains the same type and value as other. Also true if both 'Any' objects are empty.

bool operator!=

(

Any const &

other

)

const

Check if this object differs from other by type or value.

operator bool

(

)

const

Convert 'Any' to false if this object is empty, true otherwise.

bool empty

(

)

const

Check if this object is empty (holds no value).

bool is_type

(

)

const

Check if this object holds a value of the given type.

bool is_readable

(

)

const

Check if this object's value is convertible to the given type. At present, this only succeeds if T matches the stored type exactly or is an arithmetic type convertible from the stored type.

T& get

(

)

Read-write access to the contained value. This throws an exception if the types don't match.

T const& get

(

)

const

Read-only access to the contained value. This throws an exception if the types don't match.

T read

(

)

const

By-value access to the stored value. This throws an exception if the stored type doesn't match T and T is not an arithmetic type.

Friends And Related Function Documentation

void swap ( Any &  l, Any &  r  )

friend

Exchange the value of objects l and r.

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The documentation for this class was generated from the following file:

• vigra/any.hxx