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      FE_DIVBYZERO, FE_INEXACT, FE_INVALID, FE_OVERFLOW, FE_UNDERFLOW, FE_ALL_EXCEPT

      From cppreference.com
      <cpp‎ |numeric‎ |fenv
       
       
       
      Floating-point environment
      Functions
      (C++11)(C++11)
      (C++11)(C++11)
      Macro constants
      FE_ALL_EXCEPTFE_DIVBYZEROFE_INEXACTFE_INVALIDFE_OVERFLOWFE_UNDERFLOW
      (C++11)(C++11)(C++11)(C++11)(C++11)(C++11)
      (C++11)
       
      Defined in header<cfenv>
      #define FE_DIVBYZERO    /*implementation defined power of 2*/
      (since C++11)
      #define FE_INEXACT      /*implementation defined power of 2*/
      (since C++11)
      #define FE_INVALID      /*implementation defined power of 2*/
      (since C++11)
      #define FE_OVERFLOW     /*implementation defined power of 2*/
      (since C++11)
      #define FE_UNDERFLOW    /*implementation defined power of 2*/
      (since C++11)
      #define FE_ALL_EXCEPT   FE_DIVBYZERO | FE_INEXACT | \

                              FE_INVALID | FE_OVERFLOW |  \

                              FE_UNDERFLOW
      (since C++11)

      All these macro constants (exceptFE_ALL_EXCEPT) expand to integer constant expressions that are distinct powers of 2, which uniquely identify all supported floating-point exceptions. Each macro is defined only if it is supported.

      The macro constantFE_ALL_EXCEPT, which expands to the bitwise OR of all otherFE_*, is always defined and is zero if floating-point exceptions are not supported by the implementation.

      Constant Explanation
      FE_DIVBYZERO pole error occurred in an earlier floating-point operation
      FE_INEXACT inexact result: rounding was necessary to store the result of an earlier floating-point operation
      FE_INVALID domain error occurred in an earlier floating-point operation
      FE_OVERFLOW the result of the earlier floating-point operation was too large to be representable
      FE_UNDERFLOW the result of the earlier floating-point operation was subnormal with a loss of precision
      FE_ALL_EXCEPT bitwise OR of all supported floating-point exceptions

      The implementation may define additional macro constants in<cfenv> to identify additional floating-point exceptions. All such constants begin withFE_ followed by at least one uppercase letter.

      Seemath_errhandling for further details.

      [edit]Example

      [edit]
      Run this code
      #include <cfenv>#include <cmath>#include <iostream> // #pragma STDC FENV_ACCESS ON volatiledouble zero=0.0;// volatile not needed where FENV_ACCESS is supportedvolatiledouble one=1.0;// volatile not needed where FENV_ACCESS is supported int main(){std::feclearexcept(FE_ALL_EXCEPT);std::cout<<"1.0/0.0 = "<<1.0/ zero<<'\n';if(std::fetestexcept(FE_DIVBYZERO))std::cout<<"division by zero reported\n";elsestd::cout<<"division by zero not reported\n"; std::feclearexcept(FE_ALL_EXCEPT);std::cout<<"1.0/10 = "<< one/10<<'\n';if(std::fetestexcept(FE_INEXACT))std::cout<<"inexact result reported\n";elsestd::cout<<"inexact result not reported\n"; std::feclearexcept(FE_ALL_EXCEPT);std::cout<<"sqrt(-1) = "<<std::sqrt(-1)<<'\n';if(std::fetestexcept(FE_INVALID))std::cout<<"invalid result reported\n";elsestd::cout<<"invalid result not reported\n";}

      Possible output:

      1.0/0.0 = infdivision by zero reported1.0/10 = 0.1inexact result reportedsqrt(-1) = -naninvalid result reported

      [edit]See also

      defines the error handling mechanism used by the common mathematical functions
      (macro constant)[edit]
      C documentation forfloating point exception macros
      Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/numeric/fenv/FE_exceptions&oldid=169745"

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