The type must work with < operator and the result should have standard semantics.
The type T
satisfies LessThanComparable if.
Given.
a
, b
, and c
, expressions of type T
or const T
The following expressions must be valid and have their specified effects.
Expression | Return type | Requirements |
---|---|---|
a < b | implicitly convertible to bool | Establishes strict weak ordering relation with the following properties
|
To satisfy this requirement, types that do not have built-in comparison operators have to provide a user-defined operator<
For the types that are both EqualityComparable and LessThanComparable, the C++ standard library makes a distinction between equality, which is the value of the expression a == b
and equivalence, which is the value of the expression !(a < b) && !(b < a)
.
a BinaryPredicate that establishes an ordering relation (named requirement) |
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