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

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.

Parameters

(none).

Return value

Pointer or reference to the contained value.

Exceptions

(none).

Notes

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

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