Converts s to uppercase (by performing Unicode uppercase mapping) in place.
For a few characters string length may increase after the transformation,
in such a case the function reallocates exactly once.
If s does not have any lowercase characters, then s is unaltered.
Converts s to uppercase (by performing Unicode uppercase mapping) in place. For a few characters string length may increase after the transformation, in such a case the function reallocates exactly once. If s does not have any lowercase characters, then s is unaltered.