towupper
From cppreference.com
                    
                                        
                    
                    
                                                            
                    | Defined in header  <wctype.h> | ||
| wint_t towupper( wint_t ch ); | ||
Converts the given wide character to uppercase, if possible.
| Contents | 
[edit] Parameters
| ch | - | wide character to be converted | 
[edit] Return value
Uppercase version of ch or unmodified ch if no uppercase version is listed in the current C locale.
[edit] Notes
Only 1:1 character mapping can be performed by this function, e.g. the uppercase form of 'ß' is (with some exceptions) the two-character string "SS", which cannot be obtained by towupper.
[edit] See also
| converts a wide character to lowercase (function) | |
| converts a character to uppercase (function) | |
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C++ documentation for towupper
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