The <float.h> include file defines constants that specify the ranges of binary floating-point data types. For example, the maximum number of digits for objects of type double or the minimum exponent for objects of type float. In addition, if the macro variable __STDC_WANT_DEC_FP__ is defined, the include file also defines constants that specify ranges of decimal floating-point data types. For example, the maximum number of digits for objects of type _Decimal64 or the minimum exponent for objects of type _Decimal32.