[C++] token 요약

Token Class	Examples
Indentifier	vector, foo_bar, x3
Keyword	int, for, virtual
Character literal	'x', '\n', 'U'
Integer literal	12, 012, 0x12
Floating-point literal	1.2, 1.2e-3, 1.2L
String literal	"Hello!", R"("World"!)"
Operator	+=, %, <<
Punctuation	;, ,, {, }, (, )
Preprocessor notation	#, ##