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std::binder1st -> boost::binder1st

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[SVN r9681]
This commit is contained in:
Jeremy Siek 2001-03-29 16:18:41 +00:00
parent 836d8b1c64
commit 85c2a35257
1 changed files with 35 additions and 3 deletions
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38
transform_iterator_example.cpp
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@ -9,6 +9,38 @@
#include <iostream>
#include <boost/iterator_adaptors.hpp>
// What a bummer. We can't use std::binder1st with transform iterator
// because it does not have a default constructor. Here's a version
// that does.
namespace boost {
template <class Operation>
class binder1st
: public std::unary_function<typename Operation::second_argument_type,
typename Operation::result_type> {
protected:
Operation op;
typename Operation::first_argument_type value;
public:
binder1st() { } // this had to be added!
binder1st(const Operation& x,
const typename Operation::first_argument_type& y)
: op(x), value(y) {}
typename Operation::result_type
operator()(const typename Operation::second_argument_type& x) const {
return op(value, x);
}
};
template <class Operation, class T>
inline binder1st<Operation> bind1st(const Operation& op, const T& x) {
typedef typename Operation::first_argument_type arg1_type;
return binder1st<Operation>(op, arg1_type(x));
}
} // namespace boost
int
main(int, char*[])
{
@ -20,11 +52,11 @@ main(int, char*[])
int x[] = { 1, 2, 3, 4, 5, 6, 7, 8 };
const int N = sizeof(x)/sizeof(int);
typedef std::binder1st< std::multiplies<int> > Function;
typedef boost::binder1st< std::multiplies<int> > Function;
typedef boost::transform_iterator_generator<Function, int*>::type doubling_iterator;
doubling_iterator i(x, std::bind1st(std::multiplies<int>(), 2)),
i_end(x + N, std::bind1st(std::multiplies<int>(), 2));
doubling_iterator i(x, boost::bind1st(std::multiplies<int>(), 2)),
i_end(x + N, boost::bind1st(std::multiplies<int>(), 2));
std::cout << "multiplying the array by 2:" << std::endl;
while (i != i_end)