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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:45:59 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:45:59 +0000 |
commit | 19fcec84d8d7d21e796c7624e521b60d28ee21ed (patch) | |
tree | 42d26aa27d1e3f7c0b8bd3fd14e7d7082f5008dc /src/boost/libs/hana/example/tutorial/concepts.cpp | |
parent | Initial commit. (diff) | |
download | ceph-19fcec84d8d7d21e796c7624e521b60d28ee21ed.tar.xz ceph-19fcec84d8d7d21e796c7624e521b60d28ee21ed.zip |
Adding upstream version 16.2.11+ds.upstream/16.2.11+dsupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/boost/libs/hana/example/tutorial/concepts.cpp')
-rw-r--r-- | src/boost/libs/hana/example/tutorial/concepts.cpp | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/src/boost/libs/hana/example/tutorial/concepts.cpp b/src/boost/libs/hana/example/tutorial/concepts.cpp new file mode 100644 index 000000000..751b47309 --- /dev/null +++ b/src/boost/libs/hana/example/tutorial/concepts.cpp @@ -0,0 +1,64 @@ +// Copyright Louis Dionne 2013-2017 +// Distributed under the Boost Software License, Version 1.0. +// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt) + +#include <boost/hana/core/default.hpp> +#include <boost/hana/core/tag_of.hpp> +#include <boost/hana/integral_constant.hpp> + +#include <string> +#include <type_traits> +namespace hana = boost::hana; + + +namespace with_special_base_class { +//! [special_base_class] +struct special_base_class { }; + +template <typename T> +struct print_impl : special_base_class { + template <typename ...Args> + static constexpr auto apply(Args&& ...) = delete; +}; + +template <typename T> +struct Printable + : hana::integral_constant<bool, + !std::is_base_of<special_base_class, print_impl<hana::tag_of_t<T>>>::value + > +{ }; +//! [special_base_class] + +//! [special_base_class_customize] +struct Person { std::string name; }; + +template <> +struct print_impl<Person> /* don't inherit from special_base_class */ { + // ... implementation ... +}; + +static_assert(Printable<Person>::value, ""); +static_assert(!Printable<void>::value, ""); +//! [special_base_class_customize] +} + +namespace actual { +//! [actual] +template <typename T> +struct print_impl : hana::default_ { + template <typename ...Args> + static constexpr auto apply(Args&& ...) = delete; +}; + +template <typename T> +struct Printable + : hana::integral_constant<bool, + !hana::is_default<print_impl<hana::tag_of_t<T>>>::value + > +{ }; +//! [actual] + +static_assert(!Printable<void>::value, ""); +} + +int main() { } |