line length: Many C++ compilers impose a maximum line length (both for physical source lines and for logical source lines).
escape characters: The backslash character () is used as an escape character, allowing a programmer to include characters that would normally have a special meaning for the compiler.
alternative characters: Some C++ compilers support the ANSI C trigraphs (see C).
multibyte characters: C++ supports both wide characters and multibyte characters.
Wide characters are binary characters that are more than one byte, typically used for expressing large alphabets.
Multibyte characters are the external representation of a wide character, in either the source or execution character set.
comments: Comments are started by the occurrence of the two character sequence /* at any time other than within a character or string constant. Comments are terminated by the two character sequence */. Comments can also start with // and end with the end of the line.
tokens A C++ compiler always collects characters into the longest possible tokens, even if the result is not valid C++. White space always divides tokens. White space must be used to separate an identifier, reserved word, integer constant, floating point constant from a following identifier, reserved word, integer constant, or floating point constant. operators: C++ has 15 simple operators ( ! % ^ & * - + = ~ | . < > / ? ), 11 compound assignment operators ( += -= *= /= %= = &= ^= |= == ), and 10 other compound operators ( -> ++ -- > = != && || ). separators: C++ has 9 separator tokens ( ( ) [ ] { } , ; : ).