std::nan, std::nanf, std::nanl

 

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add_sat (C++26) sub_sat (C++26) saturate_cast (C++26)	mul_sat (C++26) div_sat (C++26)
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iota (C++11) ranges::iota (C++23) accumulate inner_product adjacent_difference partial_sum	reduce (C++17) transform_reduce (C++17) inclusive_scan (C++17) exclusive_scan (C++17) transform_inclusive_scan (C++17) transform_exclusive_scan (C++17)
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has_single_bit (C++20)     bit_cast (C++20) bit_ceil (C++20) bit_floor (C++20) bit_width (C++20) rotl (C++20) rotr (C++20)	popcount (C++20) countl_zero (C++20) countl_one (C++20) countr_zero (C++20) countr_one (C++20) byteswap (C++23) endian (C++20)

 

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abs(int)labsllabsimaxabs (C++11)   abs(float)fabs divldivlldivimaxdiv (C++11)	fmod remainder (C++11)   remquo (C++11) fma (C++11) fmax (C++11) fmin (C++11) fdim (C++11) nannanfnanl (C++11)(C++11)(C++11)
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exp exp2 (C++11) expm1 (C++11)	log log10 log1p (C++11) log2 (C++11)
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sqrt cbrt (C++11)	hypot (C++11) pow
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sin cos tan asin acos atan atan2	sinh cosh tanh asinh (C++11) acosh (C++11) atanh (C++11)
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erf (C++11) erfc (C++11)	lgamma (C++11) tgamma (C++11)

Nearest integer floating point operations
ceil floor roundlroundllround (C++11)(C++11)(C++11)	trunc (C++11) nearbyint (C++11) rintlrintllrint (C++11)(C++11)(C++11)
Floating point manipulation functions
ldexp scalbnscalbln (C++11)(C++11) ilogb (C++11) logb (C++11)	frexp modf nextafternexttoward (C++11)(C++11) copysign (C++11)
Classification and comparison
fpclassify (C++11) isfinite (C++11) isinf (C++11) isnan (C++11) isnormal (C++11) signbit (C++11)	isgreater (C++11) isgreaterequal (C++11) isless (C++11) islessequal (C++11) islessgreater (C++11) isunordered (C++11)
Types
div_t ldiv_t lldiv_t (C++11)	imaxdiv_t (C++11) float_t (C++11) double_t (C++11)
Macro constants
HUGE_VALFHUGE_VALHUGE_VALL (C++11)(C++11) math_errhandlingMATH_ERRNOMATH_ERREXCEPT (C++11)   INFINITY (C++11) NAN (C++11)	Classification FP_NORMALFP_SUBNORMALFP_ZEROFP_INFINITEFP_NAN (C++11)(C++11)(C++11)(C++11)(C++11)

 

Template:ddcl list begin <tr class="t-dsc-header">

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Defined in header <cmath>

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<td></td> <td></td> </tr> <tr class="t-dcl ">

<td >

float nanf( const char* arg );

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<td class="t-dcl-nopad"> </td> <td > (since C++11) </td> </tr> <tr class="t-dcl ">

<td >

double nan( const char* arg );

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<td class="t-dcl-nopad"> </td> <td > (since C++11) </td> </tr> <tr class="t-dcl ">

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long double nanl( const char* arg );

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<td class="t-dcl-nopad"> </td> <td > (since C++11) </td> </tr> Template:ddcl list end

Converts the implementation-defined character string arg into the corresponding quiet NaN value. The call std::nan("string") is equivalent to the call std::strtod("NAN(string)", (char**)NULL);.

Parameters

arg

-

narrow character string identifying the contents of a NaN, or an empty string

Return value

The NaN value that corresponds to the identifying string arg or zero if the implementation does not support quiet NaNs.

See also

Template:cpp/numeric/math/dcl list isnan

quiet_NaN [static]	returns a quiet NaN value of the given floating-point type (public static member function of std::numeric_limits<T>)
C documentation for nanf, nan, nanl