File: return_derivative.cpp

package info (click to toggle)
boost1.83 1.83.0-5
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid
  • size: 545,632 kB
  • sloc: cpp: 3,857,086; xml: 125,552; ansic: 34,414; python: 25,887; asm: 5,276; sh: 4,799; ada: 1,681; makefile: 1,629; perl: 1,212; pascal: 1,139; sql: 810; yacc: 478; ruby: 102; lisp: 24; csh: 6
file content (41 lines) | stat: -rw-r--r-- 1,208 bytes parent folder | download | duplicates (16)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41

// Copyright (C) 2009-2012 Lorenzo Caminiti
// Distributed under the Boost Software License, Version 1.0
// (see accompanying file LICENSE_1_0.txt or a copy at
// http://www.boost.org/LICENSE_1_0.txt)
// Home at http://www.boost.org/libs/local_function

#include <boost/config.hpp>
#ifdef BOOST_NO_CXX11_VARIADIC_MACROS
#   error "variadic macros required"
#else

#include <boost/local_function.hpp>
#include <boost/function.hpp>
#include <boost/typeof/typeof.hpp>
#include BOOST_TYPEOF_INCREMENT_REGISTRATION_GROUP()
#include <boost/detail/lightweight_test.hpp>

BOOST_TYPEOF_REGISTER_TEMPLATE(boost::function, 1)

boost::function<int (int)> derivative(boost::function<int (int)>& f, int dx) {
    int BOOST_LOCAL_FUNCTION(bind& f, const bind dx, int x) {
        return (f(x + dx) - f(x)) / dx;
    } BOOST_LOCAL_FUNCTION_NAME(deriv)

    return deriv;
}

int main(void) {
    int BOOST_LOCAL_FUNCTION(int x) {
        return x + 4;
    } BOOST_LOCAL_FUNCTION_NAME(add2)
    
    boost::function<int (int)> a2 = add2; // Reference valid where closure used.
    boost::function<int (int)> d2 = derivative(a2, 2);
    BOOST_TEST(d2(6) == 1);
    return boost::report_errors();
}

#endif // VARIADIC_MACROS