From 5068d34c08f951a7ea6257d305a1627b09a95817 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 4 May 2024 19:44:55 +0200 Subject: Adding upstream version 0.11.1. Signed-off-by: Daniel Baumann --- src/base/func_util.hh | 159 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 159 insertions(+) create mode 100644 src/base/func_util.hh (limited to 'src/base/func_util.hh') diff --git a/src/base/func_util.hh b/src/base/func_util.hh new file mode 100644 index 0000000..01a2328 --- /dev/null +++ b/src/base/func_util.hh @@ -0,0 +1,159 @@ +/** + * Copyright (c) 2020, Timothy Stack + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * * Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * * Neither the name of Timothy Stack nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND ANY + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef lnav_func_util_hh +#define lnav_func_util_hh + +#include +#include + +template +decltype(auto) +bind_mem(F&& f, FrontArg&& frontArg) +{ + return [f = std::forward(f), + frontArg = std::forward(frontArg)](auto&&... backArgs) { + return (frontArg->*f)(std::forward(backArgs)...); + }; +} + +struct noop_func { + struct anything { + template + operator T() + { + return {}; + } + // optional reference support. Somewhat evil. + template + operator T&() const + { + static T t{}; + return t; + } + }; + template + anything operator()(Args&&...) const + { + return {}; + } +}; + +namespace lnav { +namespace func { + +class scoped_cb { +public: + class guard { + public: + explicit guard(scoped_cb* owner) : g_owner(owner) {} + + guard(const guard&) = delete; + guard& operator=(const guard&) = delete; + + guard(guard&& gu) noexcept : g_owner(std::exchange(gu.g_owner, nullptr)) + { + } + + guard& operator=(guard&& gu) noexcept + { + this->g_owner = std::exchange(gu.g_owner, nullptr); + return *this; + } + + ~guard() + { + if (this->g_owner != nullptr) { + this->g_owner->s_callback = {}; + } + } + + private: + scoped_cb* g_owner; + }; + + guard install(std::function cb) + { + this->s_callback = std::move(cb); + + return guard{this}; + } + + void operator()() + { + if (s_callback) { + s_callback(); + } + } + +private: + std::function s_callback; +}; + +template>{}, int> = 0> +constexpr decltype(auto) +invoke(Fn&& f, Args&&... args) noexcept( + noexcept(std::mem_fn(f)(std::forward(args)...))) +{ + return std::mem_fn(f)(std::forward(args)...); +} + +template>{}, int> = 0> +constexpr decltype(auto) +invoke(Fn&& f, Args&&... args) noexcept( + noexcept(std::forward(f)(std::forward(args)...))) +{ + return std::forward(f)(std::forward(args)...); +} + +template +struct is_invocable { + template + static auto test(U&& p) + -> decltype((std::declval().*p)(std::declval()...), + void(), + std::true_type()); + template + static auto test(U* p) -> decltype((*p)(std::declval()...), + void(), + std::true_type()); + template + static auto test(...) -> decltype(std::false_type()); + + static constexpr bool value = decltype(test(0))::value; +}; + +} // namespace func +} // namespace lnav + +#endif -- cgit v1.2.3