Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
template <class T>
struct has_trivial_move_assign : public true_type-or-false_type {};
Inherits: If T is a (possibly cv-qualified) type with a trivial move assignment-operator then inherits from true_type, otherwise inherits from false_type.
If a type has a trivial move 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.
Compiler Compatibility: Without some (as
yet unspecified) help from the compiler, has_trivial_move_assign will never
report that a user-defined class or struct has a trivial move assign; this
is always safe, if possibly sub-optimal. In addition, in order to correctly
handle private or deleted move assignment operators then c++11's decltype is required. Currently (June 2015)
compilers that have the necessary intrinsics
to ensure that this trait "just works" include Clang, GCC-5.1 and
MSVC-12.0. You may also test to see if the necessary intrinsics
are available by checking to see if the macro BOOST_HAS_TRIVIAL_MOVE_ASSIGN
is defined.
Header: #include
<boost/type_traits/has_trivial_move_assign.hpp>
or #include <boost/type_traits.hpp>
Examples:
has_trivial_move_assign<int>inherits fromtrue_type.
has_trivial_move_assign<char*>::typeis the typetrue_type.
has_trivial_move_assign<int (*)(long)>::valueis an integral constant expression that evaluates to true.
has_trivial_move_assign<MyClass>::valueis an integral constant expression that evaluates to false.
has_trivial_move_assign<T>::value_typeis the typebool.