std::isless(3)

💖 NAME 💖

std::isless — std::isless.

okay so welcome to the std::isless(3) page from the C++ Standard Libary manual, bestie! This is the lowkey iconic “is x less than y but, like, quietly” check. 🫶

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🌸 Synopsis 🌸

Defined in header <cmath>
bool isless( float x, float y );                                    (since C++11)
bool isless( double x, double y );                                  (until C++23)

bool isless( long double x, long double y );
constexpr bool isless( /* floating-point-type */ x, /* floating-point-type */ y );  (1) (since C++23)

Additional overloads
Defined in header <cmath>
template< class Arithmetic1, class Arithmetic2 >                    (A) (since C++11)
bool isless( Arithmetic1 x, Arithmetic2 y );                        (constexpr since C++23)

1. Determines if the floating point number x is less than 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. (since C++23)

A) Additional overloads are provided for all other combinations of arithmetic types. ✨

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🎀 Parameters 🎀

• x, y — floating-point or integer values 💖

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🦋 Return value 🦋

• true if x < y, false otherwise. 💅

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🔥 Notes 🔥

The built-in operator< for floating-point numbers may raise 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 (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::isless(num1, num2) has the same effect as std::isless(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::isless(num1, num2) has the same effect as std::isless(static_cast<double>(num1), static_cast<double>(num2)). (until C++23)
• Otherwise, if num1 or num2 has type float, then std::isless(num1, num2) has the same effect as std::isless(static_cast<float>(num1), static_cast<float>(num2)).

If num1 and num2 have arithmetic types, then std::isless(num1, num2) has the same effect as std::isless(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. (since C++23) 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. 😭

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🌈 See also 🌈

• less — function object implementing x < y (class template)
• isgreater — checks if the first floating-point argument is greater than the second (C++11) (function)
• C documentation for isless 💜

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byeee bestie 🧚‍♀️💖 — this cutie came from source/version http://cppreference.com, date 2024.06.10, page std::isless(3). now go be the main character of quiet float comparisons! ✨🔥