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#ifndef OPAQUE_INCONVERTIBOOL_HPP
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#define OPAQUE_INCONVERTIBOOL_HPP
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//
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// Copyright (c) 2015, 2016
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// Kyle Markley. All rights reserved.
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//
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are met:
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//
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// 1. Redistributions of source code must retain the above copyright notice,
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// this list of conditions and the following disclaimer.
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// 2. Redistributions in binary form must reproduce the above copyright notice,
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// this list of conditions and the following disclaimer in the documentation
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// and/or other materials provided with the distribution.
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// 3. Neither the name of the author nor the names of any contributors may be
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// used to endorse or promote products derived from this software without
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// specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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// POSSIBILITY OF SUCH DAMAGE.
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//
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#include "numeric_typedef.hpp"
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namespace opaque {
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/// \addtogroup typedefs
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/// @{
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///
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/// Safer boolean type. May be implicitly created from a bool, but not
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/// from any other type, and which is not implicitly convertible to any type.
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///
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/// This is a safer substitute for built-in bool if you are concerned about
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/// implicit conversions of bool to and from other types (like int) that may
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/// be bugs. Inconvertibool prevents those implicit conversions.
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///
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/// By request of Christoph Weiss.
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///
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struct inconvertibool : opaque::numeric_typedef<bool, inconvertibool> {
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using base = opaque::numeric_typedef<bool, inconvertibool>;
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inconvertibool() = default;
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// Constructor is not explicit, but is hidden for types other than bool.
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template <typename T, typename = typename std::enable_if<
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std::is_same<bool, typename std::decay<T>::type>::value>::type>
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constexpr inconvertibool(T initial) noexcept : base(initial) { }
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};
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constexpr inline bool operator==(bool b, const inconvertibool& i) noexcept {
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return b == i.value;
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}
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constexpr inline bool operator!=(bool b, const inconvertibool& i) noexcept {
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return b != i.value;
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}
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/// @}
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}
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#endif
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