c/numeric/math/roundeven

@1-3@ Computes the nearest integer value to (in floating-point format), rounding halfway cases to nearest even integer, regardless of the current rounding mode. @4@ Type-generic macro: If has type,  is called. Otherwise, if has integer type or the type,  is called. Otherwise, is called, respectively.

Return value
If no errors occur, the nearest integer value to, rounding halfway cases to nearest even integer, is returned.

Error handling
This function is not subject to any of the errors specified in.

If the implementation supports IEEE floating-point arithmetic (IEC 60559),
 * fe_inexact is never raised
 * If is ±∞, it is returned, unmodified
 * If is ±0, it is returned, unmodified
 * If is NaN, NaN is returned