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std::optional::operator->, std::optional::operator*

From cppreference.com
< cpp‎ | utility‎ | optional
 
 
 
 
constexpr const T* operator->() const;
(1) (since C++17)
constexpr T* operator->();
(1) (since C++17)
constexpr const T& operator*() const&;
(2) (since C++17)
constexpr T& operator*() &;
(2) (since C++17)
constexpr const T&& operator*() const&&;
(2) (since C++17)
constexpr T&& operator*() &&;
(2) (since C++17)

Accesses the contained value.

1) Returns a pointer to the contained value.
2) Returns a reference to the contained value.

The behavior is undefined if *this does not contain a value.

Contents

[edit] Parameters

(none)

[edit] Return value

Pointer or reference to the contained value.

[edit] Exceptions

(none)

[edit] Notes

This operator does not check whether the optional contains a value. If checked access is needed, value() or value_or() may be used.

[edit] Example

#include <optional>
#include <iostream>
#include <string>
int main()
{
    using namespace std::string_literals;
 
    std::optional<int> opt1 = 1;
    std::cout << *opt1 << '\n';
 
    std::optional<std::string> opt2 = "abc"s;
    std::cout << opt2->size() << '\n';
}

Output:

1
3

[edit] See also

returns the contained value
(public member function) [edit]
returns the contained value if available, another value otherwise
(public member function) [edit]