__builtin_unreachable ( ) on Windows

[degski]

On Windows the function void __builtin_unreachable ( ) is undefined, and therefor the code is not functional with cl.exe. The below code snippet makes the code compile and does the 'right' thing:

#if defined( _WIN32 ) && !( defined( __clang__ ) || defined( __GNUC__ ) )
#pragma warning( disable : 4645 ) // suppress warning that non-returning function returns.
    [[noreturn]] static void __builtin_unreachable ( ) noexcept { return; /* intentional */ }
#pragma warning( default : 4645 )
#endif

Please add the above to master.

PS: I decided to wrap the library and fix the problem at the same time, also, as soon as C++20 is available, I can just delete the header and the STL will kick in automatically everywhere.

// MIT License
//
// Copyright (c) 2020 degski
//
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// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
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//
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

#pragma once

// <static_vector>

#if defined( _WIN32 ) && !( defined( __clang__ ) || defined( __GNUC__ ) )
#    pragma warning( disable : 4645 ) // suppress warning that non-returning function returns.
    [[noreturn]] static void __builtin_unreachable ( ) noexcept { return; /* intentional */ }
#    pragma warning( default : 4645 )
#endif

#include "experimental/fixed_capacity_vector"

namespace std {
    template<typename Type, std::size_t Size>
    using static_vector = experimental::fixed_capacity_vector<Type, Size>;
}

[lethal-guitar]

@degski There is also __assume(false) for MSVC: lethal-guitar/RigelEngine@b99eb2d