OFget – OFvariant

Get a pointer to the value stored in an OFvariant holding the selected alternative. More...

Functions
template<typename Alternative , typename... Alternatives>
Alternative *	OFget (OFvariant< Alternatives... > *v)
	Try to get a pointer to the given alternative from an OFvariant object. More...
template<typename Alternative , typename... Alternatives>
const Alternative *	OFget (const OFvariant< Alternatives... > *v)
	Try to get a pointer to the given alternative from an OFvariant object. More...

Detailed Description

Get a pointer to the value stored in an OFvariant holding the selected alternative.

See also

OFvisit – Apply a visitor to an OFvariant object.

Function Documentation

OFget() [1/2]

template<typename Alternative , typename... Alternatives>

const Alternative * OFget ( const OFvariant< Alternatives... > *  v )

related

Try to get a pointer to the given alternative from an OFvariant object.

Template Parameters

Alternative	the chosen alternative that shall be accessed.
Alternatives	the alternatives the given variant could hold, will be deduced automatically.

Parameters

v	a const reference to an OFvariant object potentially holding Alternative.

Returns

the address of the contained value of type const Alternative if such a value is contained. OFnullptr otherwise.

Usage Example:

const OFvariant<int,OFString> v( ... some value is assigned to v ... );
if( int* pI = OFget<int>( v ) )        // error, the result is const!
if( const int* pI = OFget<int>( v ) )  // OK
{
  COUT << "Yes, it really is an int with the value " << *pI << '!' << OFendl;
  *pI = "27"; // Error, *pI is const!
}

OFget() [2/2]

template<typename Alternative , typename... Alternatives>

Alternative * OFget ( OFvariant< Alternatives... > *  v )

related

Try to get a pointer to the given alternative from an OFvariant object.

Template Parameters

Alternative	the chosen alternative that shall be accessed.
Alternatives	the alternatives the given variant could hold, will be deduced automatically.

Parameters

v	a reference to an OFvariant object potentially holding Alternative.

Returns

the address of the contained value of type Alternative if such a value is contained. OFnullptr otherwise.

Usage Example:

OFvariant<int,OFString> v;
// ... some value is assigned to v ...
if( int* pI = OFget<int>( v ) )
{
  COUT << "Yes, it really is an int with the value " << *pI << '!' << OFendl;
  *pI = "27"; // now, let's directly assign something else
}