=
Note: Conversion is based on the latest values and formulas.
std::optional<T>:: and_then - cppreference.com 16 Nov 2024 · If *this contains a value, invokes f with the contained value as an argument, and returns the result of that invocation; otherwise, returns an empty std::optional.
std:: optional - cppreference.com 19 Feb 2025 · A common use case for optional is the return value of a function that may fail. As opposed to other approaches, such as std::pair<T, bool>, optional handles expensive-to …
std::optional<T>::value_or - cppreference.com 14 Feb 2025 · Returns the contained value if *this contains a value, otherwise returns default_value.
std::optional<T>::optional - cppreference.com 26 Jun 2024 · Constraints and supplement information 3) If std::is_copy_constructible_v<T> is false, the constructor is defined as deleted.
std::optional<T>::emplace - cppreference.com 25 Jun 2024 · Constructs the contained value in-place. If *this already contains a value before the call, the contained value is destroyed by calling its destructor.
Standard library header <optional> (C++17) - cppreference.com 12 Dec 2024 · namespace std { class bad_optional_access : public exception { public: // for the specification of the special member functions constexpr const char* what () const noexcept …
std::optional<T>::value - cppreference.com 2 May 2024 · If *this contains a value, returns a reference to the contained value. Otherwise, throws a std::bad_optional_access exception.
operator==, !=, <, <=, >, >=, <=> (std::optional) - cppreference.com 14 Feb 2025 · Performs comparison operations on optional objects. 1-7) Compares two optional objects, lhs and rhs. The contained values are compared (using the corresponding operator of …
std::make_optional - cppreference.com 11 Sep 2024 · 2) Creates an optional object constructed in-place from args.... Equivalent to returnstd::optional<T>(std::in_place, std::forward<Args>(args)...);. This overload participates in …
std::optional<T>::operator bool, std::optional<T>::has_value ... 22 May 2025 · Checks whether *this contains a value. Return value true if *this contains a value, false if *this does not contain a value. Example