std::basic_string<CharT,Traits,Allocator>::starts_with
From cppreference.com
                    
                                        
                    < cpp | string | basic string
                    
                                                            
                    |   bool starts_with(std::basic_string_view<CharT, Traits> x) const noexcept;  | 
(1) | (since C++20) | 
|   bool starts_with(CharT x) const noexcept;  | 
(2) | (since C++20) | 
|   bool starts_with(const CharT* x) const;  | 
(3) | (since C++20) | 
Checks if the string begins with the given prefix, where
1) the prefix is a string view (which may be a result of implicit conversion from another 
std::basic_string)2) the prefix is a single character
3) the prefix is a C-style string
All three overloads effectively return std::basic_string_view<CharT, Traits>(data(), size()).starts_with(x);
Parameters
| x | - | a character sequence or a single character to compare to the start of the string | 
Return value
true if the string begins with the provided prefix, false otherwise.
Example
| This section is incomplete Reason: no example  | 
See also
|    (C++20)  | 
   checks if the string ends with the given suffix   (public member function)  | 
|    (C++20)  | 
   checks if the string view starts with the given prefix   (public member function of std::basic_string_view<CharT,Traits>)  | 
|    (C++20)  | 
   checks if the string view ends with the given suffix   (public member function of std::basic_string_view<CharT,Traits>)  | 
|    compares two strings  (public member function)  | |
|    returns a substring  (public member function)  |