Boost C++ Libraries

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is_signed

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

Inherits: If T is an signed integer type or an enumerated type with an underlying signed integer type, then inherits from true_type, otherwise inherits from false_type.

C++ Standard Reference: 3.9.1, 7.2.

Compiler Compatibility: All current compilers are supported by this trait.

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

Examples:

is_signed<int> inherits from true_type.

is_signed<int const volatile>::type is the type true_type.

is_signed<unsigned int>::value is an integral constant expression that evaluates to false.

is_signed<myclass>::value is an integral constant expression that evaluates to false.

is_signed<char>::value is an integral constant expression whose value depends upon the signedness of type char.

is_signed<long long>::value is an integral constant expression that evaluates to true.

is_signed<T>::value_type is the type bool.


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