Utilities library
General utilities
Relational operators (deprecated in C++20)
Integer comparison functions
Swap and type operations
Common vocabulary types

Elementary string conversions
Type support
Basic types
Fundamental types
Fixed width integer types (C++11)
Numeric limits
C numeric limits interface
Runtime type information
Type traits
Type categories
Type properties
(C++11)(until C++20)
(C++11)(deprecated in C++20)
Type trait constants
Constant evaluation context
Supported operations
Relationships and property queries
Type modifications
Type transformations
(C++11)(until C++20)(C++17)
static const bool is_integer;
(until C++11)
static constexpr bool is_integer;
(since C++11)

The value of std::numeric_limits<T>::is_integer is true for all integer arithmetic types T and false otherwise. This constant is meaningful for all specializations.

[edit] Standard specializations

T value of std::numeric_limits<T>::is_integer
/* non-specialized */ false
bool true
char true
signed char true
unsigned char true
wchar_t true
char8_t (C++20) true
char16_t (C++11) true
char32_t (C++11) true
short true
unsigned short true
int true
unsigned int true
long true
unsigned long true
long long (C++11) true
unsigned long long (C++11) true
float false
double false
long double false

[edit] Example

#include <cstddef>
#include <cstdint>
#include <numeric>
int main()
        &&  std::numeric_limits<std::size_t>::is_integer
        &&  std::numeric_limits<std::int32_t>::is_integer
        &&  std::numeric_limits<std::int64_t>::is_integer
        &&  std::numeric_limits<decltype(42)>::is_integer
        && !std::numeric_limits<float>::is_integer
        && !std::numeric_limits<double>::is_integer
        && !std::numeric_limits<long double>::is_integer
        && !std::numeric_limits<decltype([](){})>::is_integer // P0315R4

[edit] See also

checks if a type is an integral type
(class template) [edit]
identifies signed types
(public static member constant) [edit]
identifies exact types
(public static member constant) [edit]
identifies types that represent a finite set of values
(public static member constant) [edit]