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Predicate


Category: functors 
Component type: concept 
Description
A Predicate is a Unary Function whose result represents the truth or
falsehood of some condition. A Predicate might, for example, be a
function that takes an argument of type int and returns true if the
argument is positive.
Refinement of
Unary Function
Associated types
Result type

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

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

Type requirements

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.

Complexity guarantees
Invariants
Models
Notes
See also
Adaptable Predicate, Binary Predicate, Adaptable Binary Predicate
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1999 Silicon Graphics, Inc. All Rights Reserved.
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