16 Library introduction [library]

16.4 Library-wide requirements [requirements]

16.4.4 Requirements on types and expressions [utility.requirements]

16.4.4.2 Template argument requirements [utility.arg.requirements]

Table 27: Cpp17EqualityComparable requirements [tab:cpp17.equalitycomparable]
Expression
Return type
Requirement
a == b
convertible to bool
== is an equivalence relation, that is, it has the following properties:
  • For all a, a == a.
  • If a == b, then b == a.
  • If a == b and b == c, then a == c.