運算式的摘要
primary-expression：
identifier
constant
string-literal
( expression )
generic-selection
generic-selection：
_Generic ( assignment-expression , generic-assoc-list )
generic-assoc-list：
generic-association
generic-assoc-list , generic-association
generic-association：
type-name : assignment-expression
default : assignment-expression
postfix-expression：
primary-expression
postfix-expression [ expression ]
postfix-expression ( argument-expression-listopt )
postfix-expression . identifier
postfix-expression -> identifier
postfix-expression ++
postfix-expression --
( type-name ) { initializer-list }
( type-name ) { initializer-list , }
argument-expression-list：
assignment-expression
argument-expression-list , assignment-expression
unary-expression：
postfix-expression
++ unary-expression
-- unary-expression
unary-operator cast-expression
sizeof unary-expression
sizeof ( type-name )_Alignof ( type-name )
unary-operator：下列其中一個
& * + - ~ !
cast-expression：
unary-expression
( type-name ) cast-expression
multiplicative-expression：
cast-expression
multiplicative-expression * cast-expression
multiplicative-expression / cast-expression
multiplicative-expression % cast-expression
additive-expression：
multiplicative-expression
additive-expression + multiplicative-expression
additive-expression - multiplicative-expression
shift-expression：
additive-expression
shift-expression << additive-expression
shift-expression >> additive-expression
relational-expression：
shift-expression
relational-expression < shift-expression
relational-expression > shift-expression
relational-expression <= shift-expression
relational-expression >= shift-expression
equality-expression：
relational-expression
equality-expression == relational-expression
equality-expression != relational-expression
AND-expression：
equality-expression
AND-expression & equality-expression
exclusive-OR-expression：
AND-expression
exclusive-OR-expression ^ AND-expression
inclusive-OR-expression：
exclusive-OR-expression
inclusive-OR-expression | exclusive-OR-expression
logical-AND-expression：
inclusive-OR-expression
logical-AND-expression && inclusive-OR-expression
logical-OR-expression：
logical-AND-expression
logical-OR-expression || logical-AND-expression
conditional-expression：
logical-OR-expression
logical-OR-expression ? expression : conditional-expression
assignment-expression：
conditional-expression
unary-expression assignment-operator assignment-expression
assignment-operator：下列其中一個
= *= /= %= += -= <<= >>= &= ^= |=
expression：
assignment-expression
expression , assignment-expression
constant-expression：
conditional-expression