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Diffstat (limited to 'libs/fusion/test/algorithm/fold.cpp')
| -rw-r--r-- | libs/fusion/test/algorithm/fold.cpp | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/libs/fusion/test/algorithm/fold.cpp b/libs/fusion/test/algorithm/fold.cpp new file mode 100644 index 000000000..1db081815 --- /dev/null +++ b/libs/fusion/test/algorithm/fold.cpp @@ -0,0 +1,222 @@ +/*============================================================================= + Copyright (c) 2001-2011 Joel de Guzman + Copyright (c) 2007 Dan Marsden + + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) +==============================================================================*/ +#include <boost/detail/lightweight_test.hpp> +#include <boost/fusion/container/vector/vector.hpp> +#include <boost/fusion/adapted/mpl.hpp> +#include <boost/fusion/sequence/io/out.hpp> +#include <boost/fusion/sequence/intrinsic/at.hpp> +#include <boost/fusion/container/generation/make_vector.hpp> +#include <boost/fusion/algorithm/iteration/fold.hpp> +#include <boost/fusion/algorithm/iteration/accumulate.hpp> +#include <boost/type_traits/is_same.hpp> +#include <boost/mpl/if.hpp> +#include <boost/mpl/next.hpp> +#include <boost/mpl/int.hpp> +#include <boost/mpl/vector.hpp> + +#include <boost/type_traits/remove_const.hpp> +#include <boost/type_traits/remove_reference.hpp> +#include <boost/type_traits/is_reference.hpp> + +#include <string> + +using boost::mpl::if_; +using boost::mpl::int_; +using boost::is_same; + +struct add_ints_only +{ + template<typename T> + struct result; + + template <typename State, typename T> + struct result<add_ints_only(State, T)> + { + typedef typename boost::remove_const< + typename boost::remove_reference<State>::type>::type type; + }; + + template <typename State, typename T> + State + operator()(State const& state, T const& /*x*/) const + { + return state; + } + + int + operator()(int state, int x) const + { + return x + state; + } +}; + +struct count_ints +{ + template<typename T> + struct result; + + template <typename CountT, typename T> + struct result<count_ints(CountT, T)> + { + typedef typename boost::remove_const< + typename boost::remove_reference<CountT>::type>::type state; + typedef typename boost::remove_const< + typename boost::remove_reference<T>::type>::type elem; + + typedef typename + if_< + is_same<elem, int> + , typename boost::mpl::next<state>::type + , state + >::type + type; + }; + + template <typename CountT, typename T> + typename result<count_ints(CountT, T)>::type + operator()(CountT const&, T const&) const + { + typedef typename result<count_ints(CountT, T)>::type result_; + return result_(); + } +}; + +struct appender +{ + typedef std::string result_type; + + std::string operator()(std::string const& str, char c) const + { + return str + c; + } +}; + +struct lvalue_adder +{ + template<typename Sig> + struct result; + + template<typename T0, typename T1> + struct result<lvalue_adder(T0, T1&)> + { + // Second argument still needs to support rvalues - see definition of fusion::fold + typedef T1 type; + }; + + template<typename T0, typename T1> + T1 operator()(T0 const& lhs, T1& rhs) const + { + return lhs + rhs; + } +}; + +int add(int lhs, int rhs) +{ + return lhs + rhs; +} + +int +main() +{ + using namespace boost::fusion; + namespace fusion = boost::fusion; + + { + typedef vector<int, char, int, double> vector_type; + vector_type v(12345, 'x', 678910, 3.36); + int result = fold(v, 0, add_ints_only()); + std::cout << result << std::endl; + BOOST_TEST(result == 12345+678910); + } + + { + typedef vector<int> vector_type; + vector_type v(12345); + + int n = fusion::fold(v, int_<0>(), count_ints()); + std::cout << n << std::endl; + BOOST_TEST(n == 1); + } + + { + typedef vector<int, char, int, double, int> vector_type; + vector_type v(12345, 'x', 678910, 3.36, 8756); + + int n = fusion::fold(v, int_<0>(), count_ints()); + std::cout << n << std::endl; + BOOST_TEST(n == 3); + } + + { + typedef boost::mpl::vector<int, char, int, double, int> mpl_vec; + int n = fusion::fold(mpl_vec(), int_<0>(), count_ints()); + std::cout << n << std::endl; + BOOST_TEST(n == 3); + } + + { + BOOST_TEST(fusion::fold(fusion::make_vector('a','b','c','d','e'), std::string(""), appender()) + == "abcde"); + } + + { + vector<int, int> vec(1,2); + BOOST_TEST(fusion::fold(vec, 0, lvalue_adder()) == 3); + } + + { + vector<int, int> vec(1,2); + BOOST_TEST(fusion::fold(vec, 0, add) == 3); + } + + { + typedef vector<int, char, int, double> vector_type; + vector_type v(12345, 'x', 678910, 3.36); + int result = accumulate(v, 0, add_ints_only()); + std::cout << result << std::endl; + BOOST_TEST(result == 12345+678910); + } + + { + typedef vector<int> vector_type; + vector_type v(12345); + + int n = fusion::accumulate(v, int_<0>(), count_ints()); + std::cout << n << std::endl; + BOOST_TEST(n == 1); + } + + { + typedef vector<int, char, int, double, int> vector_type; + vector_type v(12345, 'x', 678910, 3.36, 8756); + + int n = fusion::accumulate(v, int_<0>(), count_ints()); + std::cout << n << std::endl; + BOOST_TEST(n == 3); + } + + { + typedef boost::mpl::vector<int, char, int, double, int> mpl_vec; + int n = fusion::accumulate(mpl_vec(), int_<0>(), count_ints()); + std::cout << n << std::endl; + BOOST_TEST(n == 3); + } + + { + BOOST_TEST(fusion::accumulate(fusion::make_vector('a','b','c','d','e'), std::string(""), appender()) + == "abcde"); + } + + { + vector<int, int> vec(1,2); + BOOST_TEST(fusion::accumulate(vec, 0, add) == 3); + } + + return boost::report_errors(); +} + |