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c2ed70ddf9
Precisely, 1. Rename hana::_type to hana::basic_type, and document it 2. Rename hana::type<> to hana::type_c<> 3. Create and document the hana::type<> type
92 lines
1.9 KiB
C++
92 lines
1.9 KiB
C++
/*
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@copyright Louis Dionne 2015
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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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*/
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#include <boost/hana.hpp>
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#include <functional>
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#include <string>
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#include <type_traits>
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#include <utility>
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#include <vector>
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namespace hana = boost::hana;
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using namespace hana::literals;
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using namespace std::literals;
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int main() {
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{
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//! [make<Tuple>]
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auto xs = hana::make<hana::Tuple>(1, 2.2, 'a', "bcde"s);
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//! [make<Tuple>]
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}{
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//! [make<Range>]
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constexpr auto r = hana::make<hana::Range>(hana::int_<3>, hana::int_<10>);
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static_assert(r == hana::make_range(hana::int_<3>, hana::int_<10>), "");
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//! [make<Range>]
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}{
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//! [lifetime]
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std::string hello = "Hello";
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std::vector<char> world = {'W', 'o', 'r', 'l', 'd'};
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// hello is copied, world is moved-in
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auto xs = hana::make_tuple(hello, std::move(world));
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// s is a reference to the copy of hello inside xs.
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// It becomes a dangling reference as soon as xs is destroyed.
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std::string& s = xs[0_c];
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//! [lifetime]
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(void)s;
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}{
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//! [reference_wrapper]
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std::vector<int> ints = { /* huge vector of ints */ };
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std::vector<std::string> strings = { /* huge vector of strings */ };
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auto map = hana::make_map(
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hana::make_pair(hana::type_c<int>, std::ref(ints)),
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hana::make_pair(hana::type_c<std::string>, std::ref(strings))
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);
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auto& v = map[hana::type_c<int>].get();
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BOOST_HANA_RUNTIME_CHECK(&v == &ints);
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//! [reference_wrapper]
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}{
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//! [types]
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auto xs = hana::make_tuple(1, '2', "345");
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auto ints = hana::make_range(hana::int_<0>, hana::int_<100>);
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// what can we say about the types of xs and ints?
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//! [types]
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(void)xs;
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(void)ints;
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}
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}
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namespace overloading {
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//! [overloading]
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template <typename T>
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void f(std::vector<T> xs) {
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// ...
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}
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template <typename Xs, typename = std::enable_if_t<hana::is_a<hana::Tuple, Xs>()>>
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void f(Xs xs) {
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// ...
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}
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//! [overloading]
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}
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