#define MATH_ERRNO 1
(since C++11)#define MATH_ERREXCEPT 2
(since C++11)#define math_errhandling /*implementation defined*/
(since C++11)The macro constant math_errhandling expands to an expression of type int that is either equal to MATH_ERRNO, or equal to MATH_ERREXCEPT, or equal to their bitwise OR (MATH_ERRNO | MATH_ERREXCEPT).
The value of math_errhandling indicates the type of error handling that is performed by the floating-point operators and functions:
MATH_ERREXCEPT Indicates that floating-point exceptions are used: at least FE_DIVBYZERO, FE_INVALID, and FE_OVERFLOW are defined in <cfenv>. MATH_ERRNO Indicates that floating-point operations use the variable errno to report errors.
If the implementation supports IEEE floating-point arithmetic (IEC 60559), math_errhandling & MATH_ERREXCEPT is required to be non-zero.
The following floating-point error conditions are recognized:
Condition Explanation errno Floating-point exception Example Domain error The argument is outside the range in which the operation is mathematically defined (the description of each function lists the required domain errors) EDOM FE_INVALID std::acos(2) Pole error The mathematical result of the function is exactly infinite or undefined ERANGE FE_DIVBYZERO std::log(0.0), 1.0 / 0.0 Range error due to overflow The mathematical result is finite, but becomes infinite after rounding, or becomes the largest representable finite value after rounding down ERANGE FE_OVERFLOW std::pow(DBL_MAX, 2) Range error due to underflow The result is non-zero, but becomes zero after rounding, or becomes subnormal with a loss of precision ERANGE or unchanged (implementation-defined) FE_UNDERFLOW or nothing (implementation-defined) DBL_TRUE_MIN / 2 Inexact result The result has to be rounded to fit in the destination type Unchanged FE_INEXACT or nothing (unspecified) std::sqrt(2), 1.0 / 10.0 [edit] NotesWhether FE_INEXACT is raised by the mathematical library functions is unspecified in general, but may be explicitly specified in the description of the function (e.g. std::rint vs std::nearbyint).
Before C++11, floating-point exceptions were not specified, EDOM was required for any domain error, ERANGE was required for overflows and implementation-defined for underflows.
[edit] ExamplePossible output:
MATH_ERRNO is set MATH_ERREXCEPT is set log(0) = -inf errno = ERANGE (Numerical result out of range) FE_DIVBYZERO (pole error) reported[edit] See also
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4