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template <class T>
struct is_swappable : public true_type-or-false_type {};

Inherits: If the expression swap(declval<T&>(), declval<T&>()) (in a context where std::swap is visible) is valid, inherits from true_type, otherwise from false_type.

Compiler Compatibility: This trait requires C++11 for full support. On C++03 compilers it will inherit from true_type for scalar types (including integral, floating point, enumeration, pointer and pointer-to-member types) and from false_type for anything else. If MSVC standard library is used, C++17 is required for full support. In this case, in C++11 and C++14 modes the trait will inherit from true_type for types that support move construction and move assignment and from false_type for other types.

Header: #include <boost/type_traits/is_swappable.hpp> or #include <boost/type_traits.hpp>