Standard Template Library Programmer's Guide

Notation

F A type that is a model of Predicate

X The argument type of F

f Object of type F

x Object of type X

Valid expressions

Name	Expression	Return type
Function call	f(x)	Convertible to bool

Expression semantics

Name	Expression	Precondition	Semantics	Postcondition
Function call	f(x)	x is in the domain of f.	Returns true if the condition is satisfied, false if it is not.	The result is either true or false.

Models

• bool (*)(int)

See also

Adaptable Predicate, Binary Predicate, Adaptable Binary Predicate

Binary Predicate

Category: functors

Component type: concept

Description

A Binary Predicate is a Binary Function whose result represents the truth or falsehood of some condition. A Binary Predicate might, for example, be a function that takes two arguments and tests whether they are equal.

Refinement of

Binary Function

Associated types

Result type

The type returned when the Binary Predicate is called. The result type must be convertible to bool.

Notation

F A type that is a model of Binary Predicate

X The first argument type of F

Y The second argument type of F

f Object of type F

x Object of type X

y Object of type Y

Valid expressions

Name	Expression	Return type
Function call	f(x,y)	Convertible to bool

Expression semantics

Name	Expression	Precondition	Semantics	Postcondition
Function call	f(x,y)	The ordered pair (x,y) is in the domain of f.	Returns true if the condition is satisfied, false if it is not.	The result is either true or false.