資料整理于《大規(guī)模C++程序設(shè)計》???
???在頭文件的文件作用域中聲明的名稱，可能潛在地與整個系統(tǒng)中任何一個文件的文件作用域名稱沖突。即使在一個.cpp文件的文件作用域中聲明的帶有內(nèi)部連接的名稱也不能保證一定不與.h文件的作用域名稱沖突。
???主要設(shè)計規(guī)則：只有類、結(jié)構(gòu)、聯(lián)合和自由運算符函數(shù)應(yīng)該在.h文件作用域內(nèi)聲明；只有類、結(jié)構(gòu)、聯(lián)合和內(nèi)聯(lián)函數(shù)成員或（內(nèi)聯(lián)）自由運算符應(yīng)該在.h文件的作用域內(nèi)定義。
???以下代碼段闡述了上述設(shè)計規(guī)則。
?1
//
?Driver.h?????????????????????
//
?fine:comment
?2
#ifndef?INCLUDED_DRIVER?????????
//
?fine:internal?include?guard
?3
#define
?INCLUDED_DIRVER
?4
?5
#ifndef?INCLUDED_NIFTY??????????
//
?fine:redundant?include?guard
?6
#include?
"
nifty.h
"
?7
#endif
?8
?9
#define
?PI?3.141592?????????????
//
?Avoid:macro?constant
10
#define
?MIN(X)?((X)<(Y)?(X):(Y))?
//
?Avoid:macro?constant
11
12
class
?ostream;???????????????
//
?fine:?class?dec.
13
struct
?DriverInit;???????????
//
?fine:?class?dec.
14
union?Uaw;???????????????????
//
?fine:?class?dec.
15
16
extern
?
int
?globalVariable;?
//
?Avoid:external?data?dec.
17
static
?
int
?fileScopeVariable;?
//
?Avoid:internal?data?def.
18
const
?
int
?BUFFER_SIZE?
=
?
256
;?
//
?Avoid:const?data?def.
19
enum
?Boolean?
{?zero,?one?}
;??
//
?Avoid:enumeration?at?file?scope
20
typedef?
long
?BigInt;?????????
//
?typedef?at?file?scope
21
22
class
?Driver?
{
23
???
enum
?Color?
{?RED,?GREEN?}
;?
//
?fine:enumeration?in?class?scope
24
???typedef?
int
?(Dirver::
*
PMF)();?
//
?fine:?typedef?in?class?scope
25
???
static
?
int
?s_count;??????
//
?fine:static?member?dec.
26
???
int
?d_size;????
//
?fine:?member?data?def.
27
28
private
:
29
???
struct
?Pnt?
{
30
??????
short
?
int
?d_x,?d_y;
31
??????Pnt(
int
?x,?
int
?y)?
32
???????:?d_x(x),?d_y(y)?
{?}
33
???}
;??????????????
//
?fine:?private?struct?def.
34
???friend?DirverInit;??
//
?fine:?friend?dec.
35
36
public
:
37
???
int
?
static
?round(
double
?d);??
//
?fine:static?member?function?dec.
38
???
void
?setSize(
int
?size);?
//
?fine:?member?function?dec.
39
???
int
?cmp(
const
?Driver
&
)?
const
;?
//
?fine:?const?member?function?dec.
40
}
;???????????????
//
?fine:?class?def.
41
42
static
?
class
?DriverInit?
{
43
??
//
?
44
}
?DriverInit;???
//
?Special?class
45
46
int
?min(
int
?x,?
int
?y);??
//
?Avoid:?free?function?dec.
47
48
inline?
int
?max(
int
?x,?
int
?y)
49
{
50
???
return
?x?
>
?y?
?
?x?:?y;
51??? }
???
//
?Avoid?free?inline?function?def.
52
53
inline?
void
?Driver::setSize(
int
?size)?
54
{
55
???d_size?
=
?size;
56
}
????
//
?fine:?inline?member?function?def.
57
58
ostream
&
?
operator
?
<<
(ostream
&
?o,?
const
?Dirver
&
?d);??
//
?fine:?free?operator?function?def.
59
60
inline?
int
?
operator
?
==
(
const
?Driver
&
?lhs,?
const
?Dirver
&
?rhs)?
61
{
62
???
return
?compare(lhs,?rhs)?
==
?
0
;
63
}
????
//
?fine:?free?inline?operator?func.?def.
64
65
inline?
int
?Driver::round(
double
?d)
66
{
67
???retrun?d?
<
?
0
?
?
?
-
int
(
0.5
?
-
?d)?:?
int
(
0.5
?
+
?d);
68
}
????
//
?fine:?inline?static?member?func.?def.
69
70
#endif
71
72