std::char_traits::eq, std::char_traits::lt
From cppreference.com
                    
                                        
                    < cpp | string | char traits
                    
                                                            
                    | (1) | ||
| static bool eq( char_type a, char_type b ); | (until C++11) | |
| static constexpr bool eq( char_type a, char_type b ); | (since C++11) | |
| (2) | ||
| static bool lt( char_type a, char_type b ); | (until C++11) | |
| static constexpr bool lt( char_type a, char_type b ); | (since C++11) | |
Compares two characters.
1) Compares 
a and b for equality.2) Compares 
 a and b in such a way that they are totally ordered.| For the  | (since C++11) | 
| Contents | 
[edit] Parameters
| a, b | - | character values to compare | 
[edit] Return value
1) true if 
a and b are equal, false otherwise.2) true if 
a is less than b, false otherwise.[edit] Exceptions
| (none) | (until C++11) | 
| noexcept specification:   noexcept | (since C++11) | 
[edit] Complexity
Constant.


