logical_or<T>


Category: functors 
Component type: type 
Description
Logical_or<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 logical_and<T>
and x and y are objects of class T (where T is convertible
to bool) then f(x,y) returns true if and only if either x or
y is true. [1]
Example
Finds the first instance of either ' ' or '\n' in a string.
char str[MAXLEN];
...
const char* wptr = find_if(str, str + MAXLEN,
compose2(logical_or<bool>(),
bind2nd(equal_to<char>(), ' '),
bind2nd(equal_to<char>(), '\n')));
assert(wptr == str + MAXLEN  *wptr == ' '  *wptr == '\n');
Definition
Defined in function.h.
Template parameters
Parameter

Description

Default

T

The type of logical_or's arguments


Model of
Adaptable Binary Predicate, DefaultConstructible
Type requirements
T must be convertible to bool.
Public base classes
binary_function<T, T, bool>
Members
New members
All of logical_or's members are defined in the
Adaptable Binary Function and Default Constructible
requirements.
Logical_or does not introduce any new members.
Notes
[1]
Logical_and and logical_or are not very useful by themselves.
They are mainly useful because, when combined with the function object
adaptor binary_compose, they perform logical operations on other
function objects.
See also
The function object overview, logical_and, logical_not.
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1996 Silicon Graphics, Inc. All Rights Reserved.
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