forked from OSchip/llvm-project
				
			
		
			
				
	
	
		
			86 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			86 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C++
		
	
	
	
//===----------------------------------------------------------------------===//
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//
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//                     The LLVM Compiler Infrastructure
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//
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// This file is dual licensed under the MIT and the University of Illinois Open
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// Source Licenses. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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// <array>
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// template <class T, size_t N> void swap(array<T,N>& x, array<T,N>& y);
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#include <array>
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#include <cassert>
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#include "test_macros.h"
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// std::array is explicitly allowed to be initialized with A a = { init-list };.
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// Disable the missing braces warning for this reason.
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#include "disable_missing_braces_warning.h"
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struct NonSwappable {
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  NonSwappable() {}
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private:
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  NonSwappable(NonSwappable const&);
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  NonSwappable& operator=(NonSwappable const&);
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};
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template <class Tp>
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decltype(swap(std::declval<Tp>(), std::declval<Tp>()))
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can_swap_imp(int);
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template <class Tp>
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std::false_type can_swap_imp(...);
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template <class Tp>
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struct can_swap : std::is_same<decltype(can_swap_imp<Tp>(0)), void> {};
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int main()
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{
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    {
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        typedef double T;
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        typedef std::array<T, 3> C;
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        C c1 = {1, 2, 3.5};
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        C c2 = {4, 5, 6.5};
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        swap(c1, c2);
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        assert(c1.size() == 3);
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        assert(c1[0] == 4);
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        assert(c1[1] == 5);
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        assert(c1[2] == 6.5);
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        assert(c2.size() == 3);
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        assert(c2[0] == 1);
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        assert(c2[1] == 2);
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        assert(c2[2] == 3.5);
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    }
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    {
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        typedef double T;
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        typedef std::array<T, 0> C;
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        C c1 = {};
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        C c2 = {};
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        swap(c1, c2);
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        assert(c1.size() == 0);
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        assert(c2.size() == 0);
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    }
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    {
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        typedef NonSwappable T;
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        typedef std::array<T, 0> C0;
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        static_assert(can_swap<C0&>::value, "");
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        C0 l = {};
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        C0 r = {};
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        swap(l, r);
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#if TEST_STD_VER >= 11
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        static_assert(noexcept(swap(l, r)), "");
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#endif
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    }
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#if TEST_STD_VER >= 11
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    {
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        // NonSwappable is still considered swappable in C++03 because there
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        // is no access control SFINAE.
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        typedef NonSwappable T;
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        typedef std::array<T, 42> C1;
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        static_assert(!can_swap<C1&>::value, "");
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    }
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#endif
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}
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