关于C++ Primer中的优先级问题

问题是，这个：

“Table 5.4 presents the full set of operators ordered by precedence. The table is organized into segments separated by double lines. Operators in each segment have the same precedence, and have higher precedence than operators in sub-sequent segments. For example, the prefix increment and dereference operators share the same precedence and have higher precedence than the arithmetic or relational operators. We have seen most of these operators, although a few will not be defined until later chapters.”

可是哪里有double line啊，这都是一样的阿，达人请给画一下，万分感谢。还有“：”操作符的优先级应该也不低吧，左连接？这里没有啊。

Table 5.4. Operator Precedence

Associativity
and Operator

Function

Use

See
Page

L

::

global scope

:: name

p. 450

L

::

class scope

class :: name

p. 85

L

::

namespace scope

namespace :: name

p. 78

L

.

member selectors

object . member

p. 25

L

->

member selectors

pointer -> member

p. 164

L

[]

subscript

variable [ expr ]

p. 113

L

()

function call

name (expr_list)

p. 25

L

()

type construction

type (expr_list)

p. 460

R

++

postfix increment

lvalue++

p. 162

R

--

postfix decrement

lvalue--

p. 162

R

typeid

type ID

typeid (type)

p. 775

R

typeid

run-time type ID

typeid (expr)

p. 775

R

explicit cast

type conversion

cast_name <type>(expr)

p. 183

R

sizeof

size of object

sizeof expr

p. 167

R

sizeof

size of type

sizeof(type)

p. 167

R

++

prefix increment

++ lvalue

p. 162

R

--

prefix decrement

-- lvalue

p. 162

R

~

bitwise NOT

~expr

p. 154

R

!

logical NOT

!expr

p. 152

R

-

unary minus

-expr

p. 150

R

+

unary plus

+expr

p. 150

R

*

dereference

*expr

p. 119

R

&

address-of

&expr

p. 115

R

()

type conversion

(type) expr

p. 186

R

new

allocate object

new type

p. 174

R

delete

deallocate object

delete expr

p. 176

R

delete[]

deallocate array

delete[] expr

p. 137

L

->*

ptr to member select

ptr ->* ptr_to_member

p. 783

L

.*

ptr to member select

obj .*ptr_to_member

p. 783

L

*

multiply

expr * expr

p. 149

L

/

divide

expr / expr

p. 149

L

%

modulo (remainder)

expr % expr

p. 149

L

+

add

expr + expr

p. 149

L

-

subtract

expr - expr

p. 149

L

<<

bitwise shift left

expr << expr

p. 154

L

>>

bitwise shift right

expr >> expr

p. 154

L

<

less than

expr < expr

p. 152

L

<=

less than or equal

expr <= expr

p. 152

L

>

greater than

expr > expr

p. 152

L

>=

greater than or equal

expr >= expr

p. 152

L

==

equality

expr == expr

p. 152

L

!=

inequality

expr != expr

p. 152

L

&

bitwise AND

expr & expr

p. 154

L

^

bitwise XOR

expr ^ expr

p. 154

L

|

bitwise OR

expr | expr

p. 154

L

&&

logical AND

expr && expr

p. 152

L

||

logical OR

expr || expr

p. 152

R

?:

conditional

expr ? expr : expr

p. 165

R

=

assignment

lvalue = expr

p. 159

R

*=, /=, %=,

compound assign

lvalue += expr, etc.

p. 159

R

+=, -=,

   

p. 159

R

<<=, >>=,

   

p. 159

R

&=,|=, ^=

   

p. 159

R

throw

throw exception

throw expr

p. 216

L

,

comma

expr , expr

p. 168