Namespaces
Variants
Views
Actions

std::unique_ptr<T,Deleter>::operator*, std::unique_ptr<T,Deleter>::operator->

From cppreference.com
< cpp‎ | memory‎ | unique ptr
 
 
Utilities library
General utilities
Relational operators (deprecated in C++20)
 
Dynamic memory management
Uninitialized memory algorithms
(C++17)
(C++17)
(C++20)
(C++17)
Constrained uninitialized
memory algorithms
C Library

Allocators
Memory resources
Garbage collection support
(C++11)(until C++23)
(C++11)(until C++23)
(C++11)(until C++23)
(C++11)(until C++23)
(C++11)(until C++23)
(C++11)(until C++23)
Uninitialized storage
(until C++20*)
(until C++20*)
Explicit lifetime management
 
 
typename std::add_lvalue_reference<T>::type operator*() const
    noexcept(noexcept(*std::declval<pointer>()));
(1) (since C++11)
(constexpr since C++23)
pointer operator->() const noexcept;
(2) (since C++11)
(constexpr since C++23)

operator* and operator-> provide access to the object owned by *this.

The behavior is undefined if get() == nullptr.

These member functions are only provided for unique_ptr for the single objects i.e. the primary template.

Contents

[edit] Parameters

(none)

[edit] Return value

1) Returns the object owned by *this, equivalent to *get().
2) Returns a pointer to the object owned by *this, i.e. get().

[edit] Exceptions

1) May throw if pointer has a throwing operator*.

[edit] Notes

The use of std::add_lvalue_reference is to make it possible to instantiate std::unique_ptr<void> since void& isn't allowed in C++ while std::add_lvalue_reference<void> produces void. See LWG673 for details.

[edit] Example

#include <iostream>
#include <memory>
 
struct Foo
{
    void bar() { std::cout << "Foo::bar\n"; }
};
 
void f(const Foo&) 
{
    std::cout << "f(const Foo&)\n";
}
 
int main() 
{
    std::unique_ptr<Foo> ptr(new Foo);
 
    ptr->bar();
    f(*ptr);
}

Output:

Foo::bar
f(const Foo&)

[edit] Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 2762 C++11 operator* might be potentially-throwing even if
*get() was noexcept
a conditional exception specification added

[edit] See also

returns a pointer to the managed object
(public member function) [edit]