Буквальный анализируется во время компиляции, и результат возвращается в виде<llong<...>>.
Note
We use llong<...> instead of ullong<...> because using an unsigned type leads to unexpected behavior when doing stuff like -1_c. If we used an unsigned type, -1_c would be something like ullong<-1> which is actually ullong<something huge>.
Example
using namespace hana::literals; // contains the _c suffix
constexpr auto boost::hana::literals::operator""_s
(
)
Создает строку времени компиляции из строки буквально.
Буквальная строка анализируется во время компиляции, и результат возвращается как<hana::string>. Эта функция является расширением, которое отключено по умолчанию; см. Ниже для деталей.
Note
Only narrow string literals are supported right now; support for fancier types of string literals like wide or UTF-XX might be added in the future if there is a demand for it. See this issue if you need this.
Warning
This user-defined literal is an extension which requires a special string literal operator that is not part of the standard yet. That operator is supported by both Clang and GCC, and several proposals were made for it to enter C++17. However, since it is not standard, it is disabled by default and defining the BOOST_HANA_CONFIG_ENABLE_STRING_UDL config macro is required to get this operator. Hence, if you want to stay safe, just use the BOOST_HANA_STRING macro instead. If you want to be fast and furious (I do), define BOOST_HANA_CONFIG_ENABLE_STRING_UDL.
Example
// Copyright Louis Dionne 2013-2016
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
