Islessequal
Defined in header <cmath>
.
Description
Determines if the floating point number x
is less than or equal to the floating-point number y
, without setting floating-point exceptions.
The library provides overloads for all cv-unqualified floating-point types as the type of the parameters x
and y
(od C++23).
Additional Overloads are provided for all other combinations of arithmetic types.
Declarations
- C++23
- C++11
// 1)
constexpr bool islessequal( /* floating-point-type */ x,
/* floating-point-type */ y );
// 2)
template< class Arithmetic1, class Arithmetic2 >
constexpr bool islessequal( Arithmetic1 x, Arithmetic2 y );
// 1)
bool islessequal( float x, float y );
// 2)
bool islessequal( double x, double y );
// 3)
bool islessequal( long double x, long double y );
// 4)
template< class Arithmetic1, class Arithmetic2 >
bool islessequal( Arithmetic1 x, Arithmetic2 y );
Parameters
x
, y
- floating-point or integer values
Return value
true
if x <= y
, false
otherwise.
Notes
The built-in operator >=
for floating-point numbers may set FE_INVALID
if one or both of the arguments is NaN
. This function is a "quiet" version of operator >=
.
The additional overloads are not required to be provided exactly as Additional Overloads.
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::islessequal(num1, num2)
has the same effect as
std::islessequal(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::islessequal(num1, num2)
has the same effect as
std::islessequal(static_cast<double>(num1), static_cast<double>(num2))
.
Otherwise, if num1
or num2
has type float, then
std::islessequal(num1, num2)
has the same effect as
std::islessequal(static_cast<float>(num1), static_cast<float>(num2))
. (do C++23)
If num1
and num2
have arithmetic types, then
std::islessequal(num1, num2)
has the same effect as
std::islessequal(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.