Here begins the alphabetic reference. This chapter presents each language keyword with a syntax summary, description, and, in some cases, an example. The syntax summaries use a modified BNF (Backus Normal Form or Backus-Naur Form):
Terminal symbols (keywords and operator symbols) are in
a constant-width typeface.
To avoid ambiguity, a terminal symbol that might be mistaken for
a BNF metacharacter (e.g., a vertical bar or a square bracket) is
enclosed in quotes (e.g., "
Nonterminal symbols (syntax elements) are in an italic typeface.
Optional elements are in square brackets (
[ like this
Choices are separated by vertical bars (
A production (syntax description) is introduced with := or ::=. The traditional symbol (::=) is used for a complete definition. The abbreviated symbol (:=) is used when the righthand side is incomplete. For example, here is the complete definition of function-specifier as it is given under declaration:
function-specifier ::= explicit | inline | virtual
The following is a partial production of function-specifier:
function-specifier := inline
The abbreviated symbol (:=) lets you see that the syntax summary is incomplete. Whenever an incomplete rule is used, a cross reference (under “See Also”) leads you to the complete rule.
The starting point for parsing a C++ source file (the start symbol) is translation-unit, which you can find under declaration.
C++ syntax is complicated, and even simple statements require an understanding of ...