RHAS 4u4 gcc 3.4.6 ctype.narrow failed assertion There are specific char values that fails widen narrow conversion in the 22.locale.cytpe.narrow test. http://scottzroguewave.bravehost.com/22.locale.ctype.narrow.cpp Below shows values that narrow_chars and narrow_out differ after line 615 on 22.locale.ctype.narrow.cpp with this function: for(int k = 0; k < sizeof narrow_chars; k++) { int a = (reinterpret_cast(narrow_chars))[k]; int b = (reinterpret_cast(narrow_out))[k]; if (a != b) rw_info(0,0,__LINE__,"narrow_chars: %i, narrow_out: %i", a, b); } Output: # TEXT: narrow_chars: 96, narrow_out: 166 # TEXT: narrow_chars: 97, narrow_out: 168 # TEXT: narrow_chars: 164, narrow_out: 172 # TEXT: narrow_chars: 125, narrow_out: 180 # TEXT: narrow_chars: 126, narrow_out: 184 # TEXT: narrow_chars: 82, narrow_out: 188 # TEXT: narrow_chars: 83, narrow_out: 189 # TEXT: narrow_chars: 120, narrow_out: 190 Yu (Scott) Zhong