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[/
Copyright 2014 Peter Dimov
Distributed under the Boost Software License, Version 1.0.
See accompanying file LICENSE_1_0.txt
or copy at http://boost.org/LICENSE_1_0.txt
]
[section:addressof addressof]
[simplesect Authors]
* Brad King
* Douglas Gregor
* Peter Dimov
* Glen Fernandes
[endsimplesect]
[section Header <boost/core/addressof.hpp>]
The header `<boost/core/addressof.hpp>` defines the function
template `boost::addressof`. `boost::addressof(x)` returns the
address of `x`. Ordinarily, this address can be obtained by
`&x`, but the unary `&` operator can be overloaded. `boost::addressof`
avoids calling used-defined `operator&()`.
`boost::addressof` was originally contributed by Brad King
based on ideas from discussion with Doug Gregor.
[section Synopsis]
``
namespace boost
{
template<class T> T* addressof( T& x );
}
``
[endsect]
[section Example]
``
#include <boost/core/addressof.hpp>
struct useless_type { };
class nonaddressable {
useless_type operator&() const;
};
void f() {
nonaddressable x;
nonaddressable* xp = boost::addressof(x);
// nonaddressable* xpe = &x; /* error */
}
``
[endsect]
[section Notes]
In C++11 and above, `boost::addressof` is conditionally
`constexpr` when possible. This is indicated by
`BOOST_CORE_NO_CONSTEXPR_ADDRESSOF` not being defined.
With supported compilers, `boost::addressof` is always
`constexpr` by leveraging compiler intrinsics. This is
indicated by `BOOST_CORE_HAS_BUILTIN_ADDRESSOF` being
defined.
[endsect]
[endsect]
[endsect]
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