std::optional<T>::value

来自cppreference.com

成员函数
optional::optional
optional::~optional
optional::operator=
观察器
optional::operator->optional::operator*
optional::operator booloptional::has_value
optional::value
optional::value_or
迭代器
optional::begin (C++26)
optional::end (C++26)
单子式操作
optional::and_then (C++23)
optional::transform (C++23)
optional::or_else (C++23)
修改器
optional::emplace
optional::swap
optional::reset
非成员函数
operator==operator!=operator<operator<=operator>operator>=operator<=> (C++20)
make_optional
swap(std::optional)
推导指引
辅助类
hash<std::optional>
nullopt_t
in_place_t
bad_optional_access