swapcase!(*args)
Equivalent to String#swapcase, but modifies the receiver in place, returning str, or nil if no changes were made.
See String#downcase for meaning of and use with different encodings.
static VALUE rb_str_swapcase_bang(int argc, VALUE *argv, VALUE str) { rb_encoding *enc; OnigCaseFoldType flags = ONIGENC_CASE_UPCASE | ONIGENC_CASE_DOWNCASE; flags = check_case_options(argc, argv, flags); str_modify_keep_cr(str); enc = STR_ENC_GET(str); rb_str_check_dummy_enc(enc); if (flags&ONIGENC_CASE_ASCII_ONLY) rb_str_ascii_casemap(str, &flags, enc); else str_shared_replace(str, rb_str_casemap(str, &flags, enc)); if (ONIGENC_CASE_MODIFIED&flags) return str; return Qnil; }
