std::fmax, std::fmaxf, std::fmaxl - cppreference.com (original) (raw)

Defined in header
(1)
float fmax ( float x, float y ); double fmax ( double x, double y ); long double fmax ( long double x, long double y );		(until C++23)
constexpr /floating-point-type/ fmax ( /floating-point-type/ x, /floating-point-type/ y );		(since C++23)
float fmaxf( float x, float y );	(2)	(since C++11) (constexpr since C++23)
long double fmaxl( long double x, long double y );	(3)	(since C++11) (constexpr since C++23)
SIMD overload (since C++26)
Defined in header
template< class V0, class V1 > constexpr /math-common-simd-t/<V0, V1> fmax ( const V0& v_x, const V1& v_y );	(S)	(since C++26)
Additional overloads (since C++11)
Defined in header
template< class Integer > double fmax ( Integer x, Integer y );	(A)	(constexpr since C++23)

1-3) Returns the larger of two floating point arguments, treating NaNs as missing data (between a NaN and a numeric value, the numeric value is chosen). The library provides overloads of std::fmax for all cv-unqualified floating-point types as the type of the parameters.(since C++23)

S) The SIMD overload performs an element-wise std::fmax on v_xand v_y. (See math-common-simd-t for its definition.)	(since C++26)

A) Additional overloads are provided for all integer types, which are treated as double.	(since C++11)

[edit] Parameters

x, y	-	floating-point or integer values

[edit] Return value

If successful, returns the larger of two floating point values. The value returned is exact and does not depend on any rounding modes.

[edit] Error handling

This function is not subject to any of the error conditions specified in math_errhandling.

If the implementation supports IEEE floating-point arithmetic (IEC 60559),

If one of the two arguments is NaN, the value of the other argument is returned.
Only if both arguments are NaN, NaN is returned.

[edit] Notes

This function is not required to be sensitive to the sign of zero, although some implementations additionally enforce that if one argument is +0 and the other is -0, then +0 is returned.

The additional overloads are not required to be provided exactly as (A). They only need to be sufficient to ensure that for their first argument num1 and second argument num2:

If num1 or num2 has type long double, then std::fmax(num1, num2) has the same effect as std::fmax(static_cast<long double>(num1), static_cast<long double>(num2)). Otherwise, if num1 and/or num2 has type double or an integer type, then std::fmax(num1, num2) has the same effect as std::fmax(static_cast<double>(num1), static_cast<double>(num2)). Otherwise, if num1 or num2 has type float, then std::fmax(num1, num2) has the same effect as std::fmax(static_cast<float>(num1), static_cast<float>(num2)).	(until C++23)
If num1 and num2 have arithmetic types, then std::fmax(num1, num2) has the same effect as std::fmax(static_cast</common-floating-point-type/>(num1), static_cast</common-floating-point-type/>(num2)), where /common-floating-point-type/ is the floating-point type with the greatest floating-point conversion rank and greatest floating-point conversion subrank between the types of num1 and num2, arguments of integer type are considered to have the same floating-point conversion rank as double.If no such floating-point type with the greatest rank and subrank exists, then overload resolution does not result in a usable candidate from the overloads provided.	(since C++23)

If num1 or num2 has type long double, then std::fmax(num1, num2) has the same effect as std::fmax(static_cast<long double>(num1), static_cast<long double>(num2)). Otherwise, if num1 and/or num2 has type double or an integer type, then std::fmax(num1, num2) has the same effect as std::fmax(static_cast<double>(num1), static_cast<double>(num2)). Otherwise, if num1 or num2 has type float, then std::fmax(num1, num2) has the same effect as std::fmax(static_cast<float>(num1), static_cast<float>(num2)).

(until C++23)

If num1 and num2 have arithmetic types, then std::fmax(num1, num2) has the same effect as std::fmax(static_cast</*common-floating-point-type*/>(num1), static_cast</*common-floating-point-type*/>(num2)), where /*common-floating-point-type*/ is the floating-point type with the greatest floating-point conversion rank and greatest floating-point conversion subrank between the types of num1 and num2, arguments of integer type are considered to have the same floating-point conversion rank as double.If no such floating-point type with the greatest rank and subrank exists, then overload resolution does not result in a usable candidate from the overloads provided.

(since C++23)

[edit] Example

#include #include int main() { std::cout << "fmax(2,1) = " << std::fmax(2, 1) << '\n' << "fmax(-Inf,0) = " << std::fmax(-INFINITY, 0) << '\n' << "fmax(NaN,-1) = " << std::fmax(NAN, -1) << '\n'; }

Output:

fmax(2,1) = 2 fmax(-Inf,0) = 0 fmax(NaN,-1) = -1

[edit] See also

isgreater(C++11)	checks if the first floating-point argument is greater than the second (function) [edit]
fminfminffminl(C++11)(C++11)(C++11)	smaller of two floating point values (function) [edit]
max	returns the greater of the given values (function template) [edit]
max_element	returns the largest element in a range (function template) [edit]
minmax(C++11)	returns the smaller and larger of two elements (function template) [edit]
minmax_element(C++11)	returns the smallest and the largest elements in a range (function template) [edit]
C documentation for fmax