function
<cmath> <ctgmath>

lrint

long int lrint (double x);long int lrintf (float x);long int lrintl (long double x);
long int lrint (double x);long int lrint (float x);long int lrint (long double x);long int lrint (T x); // additional overloads for integral types
Round and cast to long integer
Rounds x to an integral value, using the rounding direction specified by fegetround, and returns it as a value of type long int.

See llrint for an equivalent function that returns a long long int.

Header <tgmath.h> provides a type-generic macro version of this function.
Additional overloads are provided in this header (<cmath>) for the integral types: These overloads effectively cast x to a double before calculations (defined for T being any integral type).

Parameters

x
Value to round.

Return Value

The value of x rounded to a nearby integral, casted to a value of type long int.
If the rounded value is outside the range of the return type, the value returned is unspecified, and a domain error or an overflow range error may occur (or none, depending on implementation).

If a domain error occurs:
- And math_errhandling has MATH_ERRNO set: the global variable errno is set to EDOM.
- And math_errhandling has MATH_ERREXCEPT set: FE_INVALID is raised.

If an overflow range error occurs:
- And math_errhandling has MATH_ERRNO set: the global variable errno is set to ERANGE.
- And math_errhandling has MATH_ERREXCEPT set: FE_OVERFLOW is raised.

Example

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/* lrint example */ #include <stdio.h> /* printf */ #include <fenv.h> /* fegetround, FE_* */ #include <math.h> /* lrint */ int main () { printf ("rounding using "); switch (fegetround()) { case FE_DOWNWARD: printf ("downward"); break; case FE_TONEAREST: printf ("to-nearest"); break; case FE_TOWARDZERO: printf ("toward-zero"); break; case FE_UPWARD: printf ("upward"); break; default: printf ("unknown"); } printf (" rounding:\n"); printf ( "lrint (2.3) = %ld\n", lrint(2.3) ); printf ( "lrint (3.8) = %ld\n", lrint(3.8) ); printf ( "lrint (-2.3) = %ld\n", lrint(-2.3) ); printf ( "lrint (-3.8) = %ld\n", lrint(-3.8) ); return 0; }

Possible output:
 Rounding using to-nearest rounding: lrint (2.3) = 2 lrint (3.8) = 4 lrint (-2.3) = -2 lrint (-3.8) = -4 


See also