c++ - Can division by non-zero still create a nan / infinity -

i have number might zeros. divide number want test if it's 0 prevent nan's , infinitys. possible still create nans / infinity because of rounding errors within division?

double x; // might 0 double y;  if(x != 0) return y / x; 

edit

thanks responses. i'll add subquestions then.

1) assuming neither x nor y nan / +inf or -inf, division results in -inf / +inf result in more cpu cycles or other unwanted behaviour? (could crash?)

2) there way prevent division resulting in infinity? using offsets , on.

can division non-zero still create nan / infinity

yes.

if ieee-754 followed then:

• if either operand nan, result nan.
• if both numerator , denumerator infinity, result nan.
• if numerator infinity, result infinity.
• if division small denumerator (or large numerator) overflows, result may infinity, depending on current rounding mode.

rules of other representations may different.

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2) there way prevent devision resulting in infinity

this should go long way in preventing that:

#include <cfenv> #include <cassert> #include <cmath> #include <limits>  // ...  static_assert(std::numeric_limits<decltype(x)>::is_iec559, "unknown floating point standard."); #pragma stdc fenv_access on int failed = std::fesetround(fe_towardzero); assert(!failed); if(x != 0 && std::isfinite(x) && std::isfinite(y))     return y / x; else     throw std::invalid_argument("informative message"); 

some compilers may need non-default options enable full ieee 754 compliance (-frounding-math on gcc).