spaceship-operator Questions
1
Solved
I know the technical answer is: because the standard says so.
But I am confused regarding the motivation:
I see nothing "library" in the defaulting the <=>: it may return some type that is ...
Kalliekallista asked 22/5, 2020 at 22:31
2
Solved
Note: I presume that this is technically duplicate of this question but:
changes to == in C++20 are quite radical, and I am not sure if
reviving 9 year question is the proper thing to do.
I ask s...
Ring asked 21/5, 2020 at 8:17
1
Solved
Consider this code:
#include <iostream>
#include <compare>
class A {
public:
int i = {};
std::strong_ordering operator<=> (A const& r) const
{
return i <=> ...
Racialism asked 28/4, 2020 at 19:25
1
Solved
Following program fails to compile with clang10 and -std=c++20
#include "clang/AST/ASTContext.h"
int main(){}
With -std=c++17 it works.
This is the compile attempt output(note that I am fine wi...
Kautz asked 26/4, 2020 at 19:15
1
Solved
#include <compare>
struct A
{
int n;
auto operator <=>(const A&) const noexcept = default;
};
struct B
{
int n;
auto operator <=>(const B& rhs) const noexcept
...
Sarena asked 5/4, 2020 at 8:26
1
Solved
I was browsing cppreference and saw that vector's comparison operations have been removed in C++20, and the spaceship operator (<=>) has been introduced. The same thing can be seen for many o...
Felix asked 2/4, 2020 at 19:4
1
Solved
Is there an easier way to achieve the effect of this function?
strong_ordering reverse(strong_ordering v) {
if (v > 0)
return strong_ordering::less;
else if (v < 0)
return strong_orderin...
Sophisticate asked 6/2, 2020 at 3:21
2
Solved
I was watching "Using C++20 three way comparison - Jonathan Müller - Meeting C++ 2019" talk and it mentioned problems with classes that contain floating point members.
Problem comes from the fact...
Auspice asked 22/12, 2019 at 14:43
3
Solved
I'm running into a strange behavior with the new spaceship operator <=> in C++20. I'm using Visual Studio 2019 compiler with /std:c++latest.
This code compiles fine, as expected:
#include &...
Aprilaprile asked 9/11, 2019 at 15:43
3
Solved
I'm running into a strange behavior with the new spaceship operator <=> in C++20. I'm using Visual Studio 2019 compiler with /std:c++latest.
This code compiles fine, as expected:
#include &...
Churchwarden asked 9/11, 2019 at 15:43
2
Solved
The definition of spaceship operator is meant to have a strong definition of ordering, but does this affect the way your client code is written or just how to define your class comparison ope...
Deeplaid asked 23/1, 2019 at 11:41
4
Solved
I was just reading the secret pseudo-constants, namely the Space fleet constant
<=><=><=> Space fleet 0
This seems to be because the outer <=> is doing something I don't ...
Keelby asked 6/7, 2018 at 4:26
1
Solved
Why do we need such an operator in C++ and how is it useful in modern C++ programming? Any real world code examples where this can be applied will help.
This question is geared to understandi...
Cyclopedia asked 4/4, 2018 at 22:7
1
Solved
Messing around in wandbox I discovered that clang will actually issue a warning if it sees <=> appear in C++17 or earlier.
warning: '<=>' is a single token in C++2a; add a space to av...
Koger asked 14/3, 2018 at 0:43
3
Solved
Herb Sutter, in his proposal for the "spaceship" operator (section 2.2.2, bottom of page 12), says:
Basing everything on <=> and its return type: This model has major advantages, s...
Pendergrass asked 2/1, 2018 at 18:22
3
Solved
There's a new comparison operator <=> in C++20. However I think in most cases a simple subtraction works well:
int my_strcmp(const char *a, const char *b) {
while (*a == *b && *a !=...
Cumulous asked 31/12, 2017 at 13:41
6
Solved
Context
While I was reading Consistent comparison, I have noticed a peculiar usage of the verb to compare:
There’s a new three-way comparison operator, <=>. The expression a <=> b
return...
Basutoland asked 26/11, 2017 at 16:38
1
With operator<=> being added into C++20, I wanted to try to reason about how to implement this operator for those cases where it's not a simple member-wise comparison.
How would you impleme...
Bani asked 15/11, 2017 at 19:15
6
Solved
What is the Ruby <=> (spaceship) operator? Is the operator implemented by any other languages?
Testa asked 6/5, 2009 at 1:27
2
Solved
In the RFC given this example:
// only values are compared
$a = (object) ["a" => "b"];
$b = (object) ["b" => "b"];
echo $a <=> $b; // 0
But when I execute it I get 1 as output ba...
Autoerotism asked 27/3, 2016 at 11:53
3
Solved
PHP 7 introduced the Spaceship (<=>) operator. What is it and how does it work?
Already asked 21/5, 2015 at 5:35
3
Solved
player1 = Player.new("moe")
player2 = Player.new("larry",60)
player3 = Player.new("curly", 125)
@players = [player1, player2, player3]
Above, I created some player objects and added them to the p...
Fennel asked 27/10, 2014 at 5:26
1
Solved
Groovy has the spaceship operator <=> which provides an easy way to implement comparisons. How can I chain it in a groovier way then the code below? In this example I want to compare the item...
Endora asked 10/1, 2014 at 15:20
4
In Ruby there is the <=> operator. In the API they do not name its name, just:
The class must define the <=> operator...
Comparable uses <=> to implement the conventional comparis...
Piscatorial asked 28/2, 2013 at 14:28
2
Solved
I am trying to override Ruby's <=> (spaceship) operator to sort apples and oranges so that apples come first sorted by weight, and oranges second, sorted by sweetness. Like so:
module Fruity
a...
Redeploy asked 17/6, 2010 at 4:10
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