Class template reference_wrapper

boost::reference_wrapper — Contains a reference to an object of type T.

Synopsis

// In header: <boost/core/ref.hpp>

template<typename T> 
class reference_wrapper {
public:
  // types
  typedef T type;

  // public member functions
  explicit reference_wrapper(T &) noexcept;
  reference_wrapper(T &&) = delete;
  template<typename Y, typename = unspecified> 
    reference_wrapper(reference_wrapper< Y >) noexcept;
  operator T&() const noexcept;
  T & get() const noexcept;
  T * get_pointer() const noexcept;
};

Description

reference_wrapper is primarily used to "feed" references to function templates (algorithms) that take their parameter by value. It provides an implicit conversion to T&, which usually allows the function templates to work on references unmodified.

`reference_wrapper` public types

typedef T type;

Type T.

`reference_wrapper` public member functions

```
explicit reference_wrapper(T & t) noexcept;
```
Constructs a reference_wrapper object that stores a reference to t.

Note

Does not throw.
```
reference_wrapper(T && t) = delete;
```
Note

Construction from a temporary object is disabled.
```
template<typename Y, typename = unspecified> 
  reference_wrapper(reference_wrapper< Y > r) noexcept;
```
Constructs a reference_wrapper object that stores the reference stored in the compatible reference_wrapper r.

Note

Only enabled when Y* is convertible to T*.

Note

Does not throw.
```
operator T&() const noexcept;
```
Note

Does not throw.

Returns:

The stored reference.
```
T & get() const noexcept;
```
Note

Does not throw.

Returns:

The stored reference.
```
T * get_pointer() const noexcept;
```
Note

Does not throw.

Returns:

A pointer to the object referenced by the stored reference.

	Note
	Does not throw.

	Note
	Construction from a temporary object is disabled.

	Note
	Only enabled when `Y` is convertible to `T`.

	Note
	Does not throw.

Boost C++ Libraries

Class template reference_wrapper

Synopsis

Description

reference_wrapper public types

reference_wrapper public member functions

`reference_wrapper` public types

`reference_wrapper` public member functions