#cplusplis

[carrieforle]

C++ Tips: std::optional<T>

std::optional<T> is a class defined in <optional>. It is added in C++17 and it presents a variable that may have a value. The value is optional, so the name.

There are 2 ways to make a std::optional

You will use 6 functions when you work with std::optional 90% of the time.

std::optional() //the constructor

std::make_optional() //make std::optional

has_value() //true if it has a value, otherwise false

value() //get the value of optional

value_or() //get the value of optional but if the optional doesn't contain one, it returns another value from the arguments

reset() //reset / destroy the contained value

Generally, std::make_optional is the way to go for creating objects unless you don't want to have a value contained when initializing.