std::numeric_limits::is_signed
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                    < cpp | types | numeric limits
                    
                                                            
                    | static const bool is_signed; | (until C++11) | |
| static constexpr bool is_signed; | (since C++11) | |
The value of std::numeric_limits<T>::is_signed is true for all signed arithmetic types T and false for the unsigned types. This constant is meaningful for all specializations.
[edit] Standard specializations
| T | value of std::numeric_limits<T>::is_signed | 
| /* non-specialized */ | false | 
| bool | false | 
| char | implementation-defined | 
| signed char | true | 
| unsigned char | false | 
| wchar_t | implementation-defined | 
| char16_t | false | 
| char32_t | false | 
| short | true | 
| unsigned short | false | 
| int | true | 
| unsigned int | false | 
| long | true | 
| unsigned long | false | 
| long long | true | 
| unsigned long long | false | 
| float | true | 
| double | true | 
| long double | true | 
[edit] See also
| (C++11) | checks if a type is signed integer type (class template) | 
| [static] | identifies integer types (public static member constant) | 
| [static] | identifies exact types (public static member constant) | 
| [static] | identifies types that represent a finite set of values (public static member constant) | 


