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less<T>

Category: functors Component type: type

Description

Less<T> is a function object. Specifically, it is an Adaptable Binary Predicate, which means it is a function object that tests the truth or falsehood of some condition. If f is an object of class less<T> and x and y are objects of class T, then f(x,y) returns true if x < y and false otherwise.

Example

Finds the first negative element in a list.
list<int> L;
...
list<int>::iterator first_negative = 
       find_if(L.begin(), L.end(), bind2nd(less<int>(), 0));
assert(first_negative == L.end() || *first_negative < 0);

Definition

Defined in the standard header functional, and in the nonstandard backward-compatibility header function.h.

Template parameters

Parameter Description Default
T The type of less's arguments.  

Model of

Adaptable Binary Predicate, DefaultConstructible

Type requirements

T is LessThan Comparable.

Public base classes

binary_function<T, T, bool>.

Members

Member Where defined Description
first_argument_type Adaptable Binary Predicate The type of the first argument: T
second_argument_type Adaptable Binary Predicate The type of the second argument: T
result_type Adaptable Binary Predicate The type of the result: bool
less() DefaultConstructible The default constructor.
bool operator()(const T& x, const T& y) Binary Function Function call operator. The return value is x < y.

New members

All of less's members are defined in the Adaptable Binary Predicate and DefaultConstructible requirements. less does not introduce any new members.

Notes

See also

The function object overview, Strict Weak Ordering, Adaptable Binary Predicate, LessThan Comparable, equal_to, not_equal_to, greater, greater_equal, less_equal

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