81 lines
1.8 KiB
C++
81 lines
1.8 KiB
C++
// Copyright Louis Dionne 2013-2017
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// Distributed under the Boost Software License, Version 1.0.
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// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
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// Make sure `assert` always triggers an assertion
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#ifdef NDEBUG
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# undef NDEBUG
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#endif
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#include <boost/fusion/include/comparison.hpp>
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#include <boost/fusion/include/make_vector.hpp>
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#include <boost/fusion/include/transform.hpp>
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#include <boost/fusion/include/vector.hpp>
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#include <boost/mpl/equal.hpp>
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#include <boost/mpl/placeholders.hpp>
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#include <boost/mpl/transform.hpp>
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#include <boost/mpl/vector.hpp>
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#include <algorithm>
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#include <cassert>
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#include <iterator>
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#include <sstream>
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#include <string>
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#include <vector>
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namespace fusion = boost::fusion;
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namespace mpl = boost::mpl;
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using namespace std::literals;
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int main() {
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{
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//! [runtime]
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auto f = [](int i) -> std::string {
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return std::to_string(i * i);
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};
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std::vector<int> ints{1, 2, 3, 4};
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std::vector<std::string> strings;
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std::transform(ints.begin(), ints.end(), std::back_inserter(strings), f);
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assert((strings == std::vector<std::string>{"1", "4", "9", "16"}));
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//! [runtime]
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}{
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//! [heterogeneous]
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auto to_string = [](auto t) {
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std::stringstream ss;
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ss << t;
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return ss.str();
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};
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fusion::vector<int, std::string, float> seq{1, "abc", 3.4f};
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fusion::vector<std::string, std::string, std::string>
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strings = fusion::transform(seq, to_string);
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assert(strings == fusion::make_vector("1"s, "abc"s, "3.4"s));
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//! [heterogeneous]
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}
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}
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//! [type-level]
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template <typename T>
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struct add_const_pointer {
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using type = T const*;
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};
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using types = mpl::vector<int, char, float, void>;
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using pointers = mpl::transform<types, add_const_pointer<mpl::_1>>::type;
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static_assert(mpl::equal<
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pointers,
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mpl::vector<int const*, char const*, float const*, void const*>
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>::value, "");
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//! [type-level]
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