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Long Double

Previous 16-bit versions of Microsoft C/C++ and Microsoft Visual C++ supported the long double, 80-bit precision data type. In Win32 programming, however, the long double data type maps to the double, 64-bit precision data type. The Microsoft run-time library provides longdouble versions of the math functions only for backward compatibility. The longdouble function prototypes are identical to the prototypes for their double counterparts, except that the longdouble data type replaces the double data type. The longdouble versions of these functions should not be used in new code.

Double Functions and Their Long Double Counterparts


Function
Long Double
Counterpart

Function
Long Double
Counterpart
acos acosl frexp frexpl
asin asinl _hypot _hypotl
atan atanl ldexp ldexpl
atan2 atan2l log logl
atof _atold log10 log10l
Bessel functions j0, j1, jn j0l, j1l, jnl _matherr _matherrl
Bessel functions y0, y1, yn y0l, y1l, ynl modf modfl
_cabs _cabsl pow powl
ceil ceill sin sinl
cos cosl sinh sinhl
cosh coshl sqrt sqrtl
exp expl strtod _strtold
fabs fabsl tan tanl
floor floorl tanh tanhl
fmod fmodl