logical_or(3C++)

Standard C++ Library
Copyright 1998, Rogue Wave Software, Inc.

NAME

logical_or

- A binary function object that returns true if either of its arguments are true.

SYNOPSIS

#include <functional>
template <class T>
struct logical_or : binary_function<T, T, bool> ;

DESCRIPTION

logical_or is a binary function object. Its operator() returns true if either x or y are true. You can pass a logical_or object to any algorithm that requires a binary function. For example, the transform algorithm applies a binary operation to corresponding values in two collections and stores the result of the function. logical_or is used in that algorithm in the following manner:

vector<bool> vec1;
vector<bool> vec2;
vector<bool> vecResult;
transform(vec1.begin(), vec1.end(),

vec2.begin(),
vecResult.begin(), logical_or<bool>());

After this call to transform, vecResult(n) contains a 1 (true) if either vec1(n) or vec2(n) is true or a 0 (false) if both vec1(n) and vec2(n) are false.

INTERFACE

template <class T>
struct logical_or : binary_function<T, T, bool> {

bool operator() (const T&, const T&) const;

};

WARNINGS

If your compiler does not support default template parameters, you always need to supply the Allocator template argument. For instance, you have to write:

vector<bool, allocator<bool> >

instead of:

vector<bool>

If your compiler does not support namespaces, then you do not need the using declaration for std.