406228d493
This is an attempt to make boost::atomic<> interface closer to the standard. It makes a difference in C++17 as it mandates copy elision, which makes this code possible: boost::atomic<int> a = 10; It also makes is_convertible<T, boost::atomic<T>> return true, which has implications on the standard library components, such as std::pair. This removes the workaround for gcc 4.7, which complains that operator=(value_arg_type) is considered ambiguous with operator=(atomic const&) in assignment expressions, even though conversion to atomic<> is less preferred than conversion to value_arg_type. We try to work around the problem from the operator= side. Added a new compile test to check that the initializing constructor is implicit.
35 lines
946 B
C++
35 lines
946 B
C++
// Copyright (c) 2018 Andrey Semashev
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//
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// Distributed under the Boost Software License, Version 1.0.
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// See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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// The test verifies that atomic<T> has an implicit conversion constructor from T.
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// This can only be tested in C++17 because it has mandated copy elision. Previous C++ versions
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// also require atomic<> to have a copy or move constructor, which it does not.
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#if __cplusplus >= 201703L
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#include <boost/atomic.hpp>
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#include <boost/static_assert.hpp>
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#include <boost/config.hpp>
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#include <type_traits>
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int main(int, char *[])
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{
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static_assert(std::is_convertible< int, boost::atomic< int > >::value, "boost::atomic<T> does not have an implicit constructor from T");
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boost::atomic< short > a = 10;
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(void)a;
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return 0;
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}
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#else // __cplusplus >= 201703L
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int main(int, char *[])
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{
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return 0;
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}
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#endif // __cplusplus >= 201703L
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