FLT_EVAL_METHOD
From cppreference.net
C++
Utilities library
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C numeric limits interface
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FLT_EVAL_METHOD
(C++11)
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Defined in header
<cfloat>
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#define FLT_EVAL_METHOD /* implementation-defined */
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(since C++11) | |
Specifies the precision in which all floating-point arithmetic operations other than assignment and cast are done.
| Value | Explanation |
| negative values except - 1 | implementation-defined behavior |
| - 1 | the default precision is not known |
| 0 | all operations and constants evaluate in the range and precision of the type used. Additionally, float_t and double_t are equivalent to float and double respectively |
| 1 | all operations and constants evaluate in the range and precision of double . Additionally, both float_t and double_t are equivalent to double |
| 2 | all operations and constants evaluate in the range and precision of long double . Additionally, both float_t and double_t are equivalent to long double |
Notes
Regardless of the value of FLT_EVAL_METHOD , any floating-point expression may be contracted , that is, calculated as if all intermediate results have infinite range and precision (unless #pragma STDC FP_CONTRACT is off).
Cast and assignment strip away any extraneous range and precision: this models the action of storing a value from an extended-precision FPU register into a standard-sized memory location.
See also
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C documentation
for
FLT_EVAL_METHOD
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