s7.assign(pc, pc + 2);
WX_ASSERT_STR_EQUAL( "de", s7 );
const wchar_t *pw = s1.c_str();
s8.assign(pw + 2, pw + 3);
WX_ASSERT_STR_EQUAL( "f", s8 );
s7.assign(pc, pc + 2);
WX_ASSERT_STR_EQUAL( "de", s7 );
const wchar_t *pw = s1.c_str();
s8.assign(pw + 2, pw + 3);
WX_ASSERT_STR_EQUAL( "f", s8 );