page = arthur o'dwyer – stuff mostly about c++

url = https://quuxplusone.github.io/blog analysed @ 2022-03-07 20:13 UTC

nullopt_t
is not equality-comparable, but
monostate
is
ranges slack standard-library-trivia today-i-learned value-semantics
On Slack , Kilian Henneberger asked for some STL types that are copyable but not equality-comparable. One example is
std::function<int()>
; see “On function_ref and string_view ” (2019-05-10). The simplest example is
struct S {};
— for compatibility with C, C++98 provided every class type with a copy constructor, but none of them with comparison operators.