std::isless
From cppreference.com
                    
                                        
                    
                    
                                                            
                    | Defined in header  <cmath> | ||
| bool isless( float x, float y ); | (1) | (since C++11) | 
| bool isless( double x, double y ); | (2) | (since C++11) | 
| bool isless( long double x, long double y ); | (3) | (since C++11) | 
| bool isless( Arithmetic x, Arithmetic y ); | (4) | (since C++11) | 
1-3) Determines if the floating point number 
x is less than the floating-point number y, without setting floating-point exceptions.4) A set of overloads or a function template for all combinations of arguments of arithmetic type not covered by (1-3). If any argument has integral type, it is cast to double.
| Contents | 
[edit] Parameters
| x | - | floating point value | 
| y | - | floating point value | 
[edit] Return value
true if x < y, false otherwise
[edit] 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<.
[edit] See also
| function object implementing x < y (class template) | |
| (C++11) | checks if the first floating-point argument is greater than the second (function) | 
| C documentation for isless | |


