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- /*
- @file
- Defines `boost::hana::experimental::type_name`.
- @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)
- */
- #ifndef BOOST_HANA_EXPERIMENTAL_TYPE_NAME_HPP
- #define BOOST_HANA_EXPERIMENTAL_TYPE_NAME_HPP
- #include <boost/hana/config.hpp>
- #include <boost/hana/string.hpp>
- #include <cstddef>
- #include <utility>
- BOOST_HANA_NAMESPACE_BEGIN namespace experimental {
- namespace detail {
- struct cstring {
- char const* ptr;
- std::size_t length;
- };
- // Note: We substract the null terminator from the string sizes below.
- template <typename T>
- constexpr cstring type_name_impl2() {
- #if defined(__clang__)
- constexpr char const* pretty_function = __PRETTY_FUNCTION__;
- constexpr std::size_t total_size = sizeof(__PRETTY_FUNCTION__) - 1;
- constexpr std::size_t prefix_size = sizeof("boost::hana::experimental::detail::cstring boost::hana::experimental::detail::type_name_impl2() [T = ") - 1;
- constexpr std::size_t suffix_size = sizeof("]") - 1;
- #else
- #error "No support for this compiler."
- #endif
- return {pretty_function + prefix_size, total_size - prefix_size - suffix_size};
- }
- template <typename T, std::size_t ...i>
- auto type_name_impl1(std::index_sequence<i...>) {
- constexpr auto name = detail::type_name_impl2<T>();
- return hana::string<*(name.ptr + i)...>{};
- }
- } // end namespace detail
- //! @ingroup group-experimental
- //! Returns a `hana::string` representing the name of the given type, at
- //! compile-time.
- //!
- //! This only works on Clang (and apparently MSVC, but Hana does not work
- //! there as of writing this). Original idea taken from
- //! https://github.com/Manu343726/ctti.
- template <typename T>
- auto type_name() {
- constexpr auto name = detail::type_name_impl2<T>();
- return detail::type_name_impl1<T>(std::make_index_sequence<name.length>{});
- }
- } BOOST_HANA_NAMESPACE_END
- #endif // !BOOST_HANA_EXPERIMENTAL_TYPE_NAME_HPP
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