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- [/
- Copyright 2007 John Maddock.
- Distributed under the Boost Software License, Version 1.0.
- (See accompanying file LICENSE_1_0.txt or copy at
- http://www.boost.org/LICENSE_1_0.txt).
- ]
- [section:has_trivial_assign has_trivial_assign]
- template <class T>
- struct has_trivial_assign : public __tof {};
-
- __inherit If T is a (possibly cv-qualified) type with a trivial assignment-operator
- then inherits from __true_type, otherwise inherits from __false_type.
- If a type has a trivial assignment-operator then the operator has the same effect
- as copying the bits of one object to the other:
- calls to the operator can be safely replaced with a call to `memcpy`.
- __compat Without some (as yet unspecified) help from the compiler,
- has_trivial_assign will never report that a user-defined class or struct has a
- trivial constructor; this is always safe, if possibly sub-optimal. In order to
- correctly handle deleted or private assignment operators, the compiler must also
- support C++11's `decltype`.
- Currently (May 2015) compilers more recent than Visual C++ 8, GCC-4.3, Greenhills 6.0,
- Intel-11.0, and Codegear have the necessary compiler __intrinsics to ensure that this
- trait "just works". You may also test to see if the necessary __intrinsics are available
- by checking to see if the macro `BOOST_HAS_TRIVIAL_ASSIGN` is defined.
- __std_ref 12.8p11.
- __header ` #include <boost/type_traits/has_trivial_assign.hpp>` or ` #include <boost/type_traits.hpp>`
- __examples
- [:`has_trivial_assign<int>` inherits from `__true_type`.]
- [:`has_trivial_assign<char*>::type` is the type `__true_type`.]
- [:`has_trivial_assign<int (*)(long)>::value` is an integral constant
- expression that evaluates to /true/.]
- [:`has_trivial_assign<MyClass>::value` is an integral constant
- expression that evaluates to /false/.]
- [:`has_trivial_assign<T>::value_type` is the type `bool`.]
- [endsect]
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