chsvlib
chsv helper source code

◆ ucp_islower()

int Chusov::String::ucp_islower ( ucp_t  ch)
noexcept

Returns a flag that indicates whether a given character is a lowercase alphabetic character in the Unicode code space.

Parameters
chis the character to check.
Returns
A nonzero value, if ch is an ASCII character, for which ucp_islower_ascii returns a nonzero value, or, if ch is not an ASCII character and belongs to the "Letter, Lowercase" normative general category. Otherwise, the function returns a zero value.

The function firstly checks if ch belongs to the ASCII code space. If it does, the function returns the result of a call to ucp_islower_ascii. Otherwise, if ch is not an ASCII character the function checks if ch belongs to the "Letter, Lowercase" general category.

The function does not take Unicode surrogate pairs into account and simply returns 0, if ch appertains the range \(\left[\textrm{0xd800}; \textrm{0xf8ff}\right]\). The function also returns 0, if ch does not belong to the range of valid Unicode code points.