问个overloading new operator的问题 - 未名空间MITBBS历史存档

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问个overloading new operator的问题

问个overloading new operator的问题# Programming - 葵花宝典

p*s2007-06-14 07:06

1 楼

在C++里,
我尝试着自己定义一个new operator,
首先我这么来一把搞一个带三个参数的new:
#define mynew new (name, type, align)
然后我overload new 和new[]:
void *operator new(size_t size, const char *ModName, memPool_t *memType, size_t alignment) throw();
new[]的overload类似于上.
然后在code里call
pool = mynew(modName, memType, alignment) myPool;
(myPool为自定义的class)
编译的时候出错,compiler不认我定义的这个operator,说
undefined reference to `operator new(unsigned int,char const*,memPool*,unsigned int).
为啥不认呢? 不会是因为我自定义带三个参数的mynew类型和operator new里四个arg
相冲突吧?

p*s2007-06-14 07:06

2 楼

嗯, 莫非是我提问的技巧太烂...
再补充一下, new operator 我在myPool里也已经做了implementation,
无非是:
inline void *myPool::operator new(size_t size, const char*ModName, memPool_t *memType, size_t aignment) {
return malloc(size);
}

【在 p****s 的大作中提到】

: 在C++里,
: 我尝试着自己定义一个new operator,
: 首先我这么来一把搞一个带三个参数的new:
: #define mynew new (name, type, align)
: 然后我overload new 和new[]:
: void *operator new(size_t size, const char *ModName, memPool_t *memType, size_t alignment) throw();
: new[]的overload类似于上.
: 然后在code里call
: pool = mynew(modName, memType, alignment) myPool;
: (myPool为自定义的class)

t*t2007-06-14 07:06

3 楼

i have no problem compiling the following program:
class mempool {};
void * operator new (size_t s, const char *, mempool*, size_t a) throw()
{
return operator new (s);
}
int main()
{
mempool* a=new("abc", NULL, 10) mempool;
}
BTW did you define ur macro literally like that? it will have some problem.

_t *memType, size_t aignment) {

【在 p****s 的大作中提到】

: 嗯, 莫非是我提问的技巧太烂...
: 再补充一下, new operator 我在myPool里也已经做了implementation,
: 无非是:
: inline void *myPool::operator new(size_t size, const char*ModName, memPool_t *memType, size_t aignment) {
: return malloc(size);
: }

p*s2007-06-14 07:06

4 楼

哦? By saying literally... 难道我前面哪里打错了什么字?
先从逻辑上说吧, 我的构架和方法是对的?

【在 t****t 的大作中提到】

: i have no problem compiling the following program:
: class mempool {};
: void * operator new (size_t s, const char *, mempool*, size_t a) throw()
: {
: return operator new (s);
: }
: int main()
: {
: mempool* a=new("abc", NULL, 10) mempool;
: }

t*t2007-06-14 07:06

5 楼

the method sounds ok to me.
#define mynew new(a, b, c)
that's what you wrote
shouldn't it be
#define mynew(a,b,c) new(a,b,c)
but what's the point of defining the macro?

【在 p****s 的大作中提到】

: 哦? By saying literally... 难道我前面哪里打错了什么字?
: 先从逻辑上说吧, 我的构架和方法是对的?

p*s2007-06-14 07:06

6 楼

Hmm, 事实上我写了两个,
#define mynew1(name) new(name)
#define mynew2(size,type,align) new(size,type,align)
至于为什么要定义这样的new macro,别问我, 我也是遵从别人的数据类型.

【在 t****t 的大作中提到】

: the method sounds ok to me.
: #define mynew new(a, b, c)
: that's what you wrote
: shouldn't it be
: #define mynew(a,b,c) new(a,b,c)
: but what's the point of defining the macro?

t*t2007-06-14 07:06

7 楼

isn't it stupid...why don't you just write
#define mynew1 new
#define mynew2 new
or why don't you just use new instead of mynew1...

【在 p****s 的大作中提到】

: Hmm, 事实上我写了两个,
: #define mynew1(name) new(name)
: #define mynew2(size,type,align) new(size,type,align)
: 至于为什么要定义这样的new macro,别问我, 我也是遵从别人的数据类型.