feedc0de/boost_iterator
1
0
Fork 0
forked from boostorg/iterator
Code Pull Requests Activity

Added function ptr support to make_transform_iterator.

Browse Source 
[SVN r1396]
This commit is contained in:
Thomas Witt
2003-06-30 22:08:20 +00:00
parent 4258cac90d
commit 405e6ba468
2 changed files with 70 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

45
include/boost/iterator/transform_iterator.hpp
View File

@@ -9,10 +9,16 @@
#ifndef BOOST_TRANSFORM_ITERATOR_23022003THW_HPP
#define BOOST_TRANSFORM_ITERATOR_23022003THW_HPP
#include <boost/function.hpp>
#include <boost/iterator.hpp>
#include <boost/iterator/detail/enable_if.hpp>
#include <boost/iterator/iterator_adaptor.hpp>
#include <boost/iterator/iterator_categories.hpp>
#include <boost/mpl/and.hpp>
#include <boost/mpl/bool.hpp>
#include <boost/type_traits/function_traits.hpp>
#include <boost/type_traits/is_const.hpp>
#include <boost/type_traits/is_function.hpp>
#include <boost/type_traits/is_reference.hpp>
#include <boost/type_traits/remove_const.hpp>
#include <boost/type_traits/remove_reference.hpp>
@@ -106,10 +112,43 @@ namespace boost
UnaryFunction m_f;
};
template <class UnaryFunction, class Iterator>
transform_iterator<UnaryFunction, Iterator> make_transform_iterator(Iterator it, UnaryFunction fun)
template <class UnaryFunctionObject, class Iterator>
transform_iterator<UnaryFunctionObject, Iterator> make_transform_iterator(Iterator it, UnaryFunctionObject fun)
{
return transform_iterator<UnaryFunction, Iterator>(it, fun);
return transform_iterator<UnaryFunctionObject, Iterator>(it, fun);
}
namespace detail {
template <class Function>
struct is_unary :
mpl::bool_<(function_traits<Function>::arity == 1)>
{};
template <class T>
struct is_unary_function :
mpl::apply_if< is_function<T>
, is_unary<T>
, mpl::bool_<false>
>::type
{};
}
//
// ToDo: Think twice wether enable_if is better than an
// static assert. Currently we get convoluted error messages
// from the above overload for any pointer that is not a
// pointer to a unary function.
//
template <class UnaryFunction, class Iterator>
typename detail::enable_if<
detail::is_unary_function<UnaryFunction>
, transform_iterator< function<UnaryFunction>, Iterator>
>::type
make_transform_iterator(Iterator it, UnaryFunction* fun)
{
return make_transform_iterator(it, function<UnaryFunction>(fun));
}
} // namespace boost

28
test/transform_iterator_test.cpp
View File

@@ -96,6 +96,10 @@ struct value_select_first
}
};
int mult_2(int arg)
{
return arg*2;
}
int
main()
@@ -128,6 +132,30 @@ main()
boost::random_access_readable_iterator_test(i, N, x);
}
// Test transform_iterator with function pointers
{
int x[N], y[N];
for (int k = 0; k < N; ++k)
x[k] = k;
std::copy(x, x + N, y);
for (int k2 = 0; k2 < N; ++k2)
x[k2] = x[k2] * 2;
boost::input_iterator_test(boost::make_transform_iterator(y, mult_2)
, x[0]
, x[1]);
boost::input_iterator_test(boost::make_transform_iterator(&y[0], mult_2)
, x[0]
, x[1]);
boost::random_access_readable_iterator_test(boost::make_transform_iterator(y, mult_2)
, N
, x);
}
// Test transform_iterator as projection iterator
{
typedef std::pair<int, int> pair_t;