spaceship-operator

In C++/STL sorting is done by using only the less-than operator. Altough I have no idea how the sorting algorithms are actually implemented, I assume that the other operations are created implicite: a > b *equals* b < a == true a == b *equals* !(a < b) && !(b < a) Compared to using a trivalue* compare function, like for example Java, is this good for performance, or why was this design decision made? My assumption is that any trivalue compareto function still has to implement these comparissons in itself, resulting in the same performance. **by trivalue compare function, I mean a compare

While I was trying to learn about C++ operators, I stumbled upon a strange comparison operator on cppreference.com , * in a table that looked like this: "Well, if these are common operators in C++, I better learn them", I thought. But all my attempts to elucidate this mystery were unsuccessful. Even here, on Stack Overflow I had no luck in my search. Is there a connection between <=> and C++ ? And if there is, what does this operator do exactly? * In the meantime cppreference.com updated that page and now contains information about the <=> operator. This is called the three-way comparison

This question already has an answer here: Reference — What does this symbol mean in PHP? 18 answers PHP 7, which will come out in November this year will introduce the Spaceship (<=>) operator. What is it and how does it work? This question already has an answer in our general reference question about PHP operators. GreenROBO This <=> operator will offer combined comparison in that it will : Return 0 if values on either side are equal Return 1 if value on the left is greater Return -1 if the value on the right is greater The rules used by the combined comparison operator are same as the