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Any Class Reference

Contains an arbitrary type. More...

#include <cxxtools/any.h>

List of all members.

Public Member Functions
template<typename T>
	Any (const T &type)
	Construct with value.
	Any ()
	Default constructor.
Any &	assign (Value *value)
	Assigns an abstract value.
	Any (const Any &val)
	Copy constructor.
	~Any ()
	Destructor.
void	clear ()
	Clear content.
bool	empty () const
	Check if empty.
Any &	swap (Any &other)
	Swap values.
const char *	typeName () const
	Check typename of assigned type.
const std::type_info &	type () const
	Returns type info of assigned type.
template<typename T>
Any &	operator= (const T &rhs)
	Assign value.
Any &	operator= (const Any &rhs)
	Assign value of other Any.
template<typename T>
bool	operator== (const T &value) const
	Check if equal.
bool	operator== (const Any &a) const
	Check if equal.
bool	operator!= (const Any &a) const
	Check if inequal.
bool	operator< (const Any &a) const
	Check if less.
const Any::Value *	value () const
Any::Value *	value ()
Friends
template<typename T>
T	any_cast (const Any &)
	Get contained value.
Classes
class	BasicValue
class	Value

---

Detailed Description

Any can contain any other type that is default- and copy constructible and less-than and equality comparable. When a value is assigned to an Any a copy is made, just like when a type is inserted in a standard C++ container. The contained type can be accessed via cxxtools::any_cast<>. It is only possible to get the contained value if the type matches

            Any a = 5;
            int i = any_cast<int>( a );    // i is 5 now
            float f = any_cast<float>( a ) // throws std::bad_cast

Anys can be compared by the contained types and values. Two Anys are considered equal when the contained values are equal and of the same type. A special case is less-than comparison, when the contained types are different. std::type_info::before will be used to decide which Any is less.

            Any a = 6;
            Any b = 6;
            Any c = '6';
            Any d = 1;

            // true, same type, same value
            a == b;

            // false, different types
            b == c;

            // true, same type and less
            d \< a;

            // implementation dependent
            d \< c;

---

Constructor & Destructor Documentation

Any

(

const T &

type

)

Constructs the Any from an value of arbitrary type. The type to be assigned must be copy-constructible. Memory is allocated to store the value. If an exception is thrown during construction, the Any will be empty and the exception is porpagated.

Parameters:

type

Value to assign

Any

(

)

Constructs an empty any. No memory needs to be allocated for empty Anys.

Any

(

const Any &

val

)

Constructs the Any by copying the value of the other Any. It is legal to assign an empty Any. If an exception is thrown during construction, the Any will be empty and the exception is porpagated.

Parameters:

val

Any to assign

~Any

(

)

Deallocates the memory needed to hold the value. This will also destruct the contained type.

---

Member Function Documentation

void clear

(

)

Removes the stored type resulting in a destructor call for the stored type. All memory required to hold the value is deallocated.

bool empty

(

)

const

Returns true if no value has been assigned, false otherwise.

Returns:

True if empty

Any& swap

(

Any &

other

)

The member function swaps the assigned values between *this and right. No exceptions are thrown, and no memory needs to be allocated.

Parameters:

other

Other any to swap value

Returns:

self reference

const char* typeName

(

)

const

Returns the typename of the currently assigned type. If the Any is empty "void" is returned.

Returns:

Typename

const std::type_info& type

(

)

const

Returns the std::type_info of the currently assigned type. If the Any is empty the type_info of void is returned.

Returns:

Type info

Any& operator=

(

const T &

rhs

)

Assigns a value of an arbitrary type. The type to be assigned must be copy-constructible. Memory is allocated to store the value. If an exception is thrown during construction, the Any will remain unaltered and the exception is porpagated.

Parameters:

rhs

Value to assign

Any& operator=

(

const Any &

rhs

)

Assignes the value of another Any by copying the value of the other Any. It is legal to assign an empty Any. If an exception is thrown during assignment, the Any will remain unchanged and the exception is porpagated.

Parameters:

rhs

Any to assign

bool operator==

(

const T &

value

)

const

Returns true if the contained type and the passed type are equal and have equal values.

Returns:

True if equal

bool operator==

(

const Any &

a

)

const

Returns true if the contained types are equal and have equal values.

Returns:

True if equal

bool operator!=

(

const Any &

a

)

const

Returns true if the contained types have different values or if the conatained types are different.

Returns:

True if different

bool operator<

(

const Any &

a

)

const

Returns true if the value of the contained type is less than the contained value of the other Any. If the contained types are different type_info::before decides which Any is less.

Returns:

True if less

---

Friends And Related Function Documentation

T any_cast

(

const Any &

any

)

[friend]

This function is used to get the contained value from an Any. It is not possible to get a float out of an Any if the contained value is an int, but the typeid's must match. It is, however, possible to get a const reference to the contained type.

Parameters:

any

Any to read to

Returns:

contained value

Exceptions:

std::bad_cast

on type mismatch

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