Defined in header <cctype> int islower( int ch ); Checks if the given character is classified as a lowercase character according to the current C locale. In the default "C" locale, islower returns true only for the lowercase letters (abcdefghijklmnopqrstuvwxyz). If islower returns true, it is guaranteed that iscntrl, isdigit, ispunct, and isspace return false for the same character in the same C locale. The behavior is undefined if the value of ch is not representable as un

Defined in header <cmath> bool isnormal( float arg ); (1) (since C++11) bool isnormal( double arg ); (2) (since C++11) bool isnormal( long double arg ); (3) (since C++11) bool isnormal( Integral arg ); (4) (since C++11) 1-3) Determines if the given floating point number arg is normal, i.e. is neither zero, subnormal, infinite, nor NaN. 4) A set of overloads or a function template accepting the from argument of any integral type. Equivalent to (2) (the ar

Defined in header <locale> template< class charT > bool islower( charT ch, const locale& loc ); Checks if the given character is classified as a lowercase alphabetic character by the given locale's std::ctype facet. Parameters ch - character loc - locale Return value Returns true if the character is classified as lowercase, false otherwise. Possible implementation template< class charT > bool islower( charT ch, const std::locale&

Defined in header <cmath> bool isnan( float arg ); (1) (since C++11) bool isnan( double arg ); (2) (since C++11) bool isnan( long double arg ); (3) (since C++11) bool isnan( Integral arg ); (4) (since C++11) 1-3) Determines if the given floating point number arg is a not-a-number (NaN) value. 4) A set of overloads or a function template accepting the from argument of any integral type. Equivalent to (2) (the argument is cast to double). Parameters a

Defined in header <cmath> bool islessgreater( float x, float y ); (1) (since C++11) bool islessgreater( double x, double y ); (2) (since C++11) bool islessgreater( long double x, long double y ); (3) (since C++11) bool islessgreater( Arithmetic x, Arithmetic y ); (4) (since C++11) 1-3) Determines if the floating point number x is less than or greater than the floating-point number y, without setting floating-point exceptions. 4) A set of overloads or a f

Defined in header <cmath> bool islessequal( float x, float y ); (1) (since C++11) bool islessequal( double x, double y ); (2) (since C++11) bool islessequal( long double x, long double y ); (3) (since C++11) bool islessequal( Arithmetic x, Arithmetic y ); (4) (since C++11) 1-3) Determines if the floating point number x is less than or equal to the floating-point number y, without setting floating-point exceptions. 4) A set of overloads or a function temp

Defined in header <cmath> bool isless( float x, float y ); (1) (since C++11) bool isless( double x, double y ); (2) (since C++11) bool isless( long double x, long double y ); (3) (since C++11) bool isless( Arithmetic x, Arithmetic y ); (4) (since C++11) 1-3) Determines if the floating point number x is less than the floating-point number y, without setting floating-point exceptions. 4) A set of overloads or a function template for all combinations of arg

Defined in header <locale> template< class charT > bool isgraph( charT ch, const locale& loc ); Checks if the given character classified as a graphic character (i.e. printable, excluding space) by the given locale's std::ctype facet. Parameters ch - character loc - locale Return value Returns true if the character is classified as graphic, false otherwise. Possible implementation template< class charT > bool isgraph( charT ch, const s

Defined in header <cmath> bool isgreater( float x, float y ); (1) (since C++11) bool isgreater( double x, double y ); (2) (since C++11) bool isgreater( long double x, long double y ); (3) (since C++11) bool isgreater( Arithmetic x, Arithmetic y ); (4) (since C++11) 1-3) Determines if the floating point number x is greater than the floating-point number (y), without setting floating-point exceptions. 4) A set of overloads or a function template for all co

Defined in header <cmath> bool isinf( float arg ); (1) (since C++11) bool isinf( double arg ); (2) (since C++11) bool isinf( long double arg ); (3) (since C++11) bool isinf( Integral arg ); (4) (since C++11) 1-3) Determines if the given floating point number arg is a positive or negative infinity. 4) A set of overloads or a function template accepting the from argument of any integral type. Equivalent to (2) (the argument is cast to double). Paramete