T :: operator int（）const与T :: operator Handle（）const不明确？ [英] T::operator int () const ambiguous with T::operator Handle () const?

问题描述

请照亮;什么类'事件''的运算符将匹配这些

两种情况[见后面的事件大纲]：


事件ev1;

活动ev2;


//案例1

//

if（ev1）

;


//案例2

//

if（ev1 || ev2）

;


我原以为''operator int（）''是唯一明显的匹配，但是我的

编译器会产生错误：


"布尔的''struct Event''转换的模糊3向选择

背景


全部我正在尝试将一个OS事件包装在一个可以被视为

a布尔的类中。任何人都可以解释这种歧义是什么以及如何解决这个问题（最好没有演员阵容）？


祝你好运

Tim


typedef struct tagHandle {} *句柄;


bool eventIsSignalled（Handle hEvent）;


struct Event

{

：

bool IsSignalled（）const {return eventIsSignalled（* this）; } $ />

运算符int（）const {return IsSignalled（）; } $ / $
运算符Handle（）const {return handle; }


私人：

处理句柄;

};

解决方案

Tim Clacy写道：

typedef struct tagHandle {} *句柄;

bool eventIsSignalled（Handle hEvent）;

struct Event
{
：
bool IsSignalled（）const {return eventIsSignalled（* this）; }}运算符int（）const {return IsSignalled（）; }
运算符Handle（）const {return handle; }


ints *和*指针可转换为布尔值（具有相同的

优先级）。所以它是暧昧的。

私人：
句柄;
};

Shezan Baig写道：

Tim Clacy写道：

typedef struct tagHandle {} * Handle;


尝试改为：

struct Handle {SomeType * realHandle; };

bool eventIsSignalled（处理hEvent）;

struct事件
{
：
bool IsSignalled（）const {return eventIsSignalled（ *这个）; }}运算符int（）const {return IsSignalled（）; }
运算符Handle（）const {return handle; }

ints *和*指针可以转换为boolean（具有相同的优先级）。所以它是暧昧的。

2005年4月29日星期五18:45:08 +0200，Tim Clacy
< no ******* @ nospamphaseone.nospamdk>写道：

请照亮;两个案例''事件''的哪个运算符将匹配这两个案例[见后面的事件大纲]：

[...] if（ev1 || ev2）
;

我原以为''operator int（）''是唯一明显的匹配，但我的
编译器会产生错误：

" ambiguous 3在布尔
上下文中从''struct Event''转换的选择

我想要做的就是将一个OS事件包装在一个可以被视为

Shezan Baig总结了模糊性。至于做什么，我会定义

''Event :: operator bool（）const''。


Kanenas

Please illuminate; what operator of class ''Event'' will get matched for these
two cases [see Event outline later]:

Event ev1;
Event ev2;

// Case 1
//
if (ev1)
;

// Case 2
//
if (ev1 || ev2)
;

I would have thought ''operator int ()'' is the only obvious match, but my
compiler generates errors:

"ambiguous 3-way choice of conversion from ''struct Event'' in Boolean
context

All I''m trying to do is wrap an OS event in a class that can be treated like
a Boolean; can anyone explain what the ambiguity is and how it can be
resolved (preferable without casts)?

Best regards
Tim

typedef struct tagHandle { }* Handle;

bool eventIsSignalled(Handle hEvent);

struct Event
{
:
bool IsSignalled() const { return eventIsSignalled(*this); }

operator int () const { return IsSignalled(); }
operator Handle () const { return handle; }

private:
Handle handle;
};

解决方案

Tim Clacy wrote:

typedef struct tagHandle { }* Handle;

bool eventIsSignalled(Handle hEvent);

struct Event
{
:
bool IsSignalled() const { return eventIsSignalled(*this); }

operator int () const { return IsSignalled(); }
operator Handle () const { return handle; }
ints *and* pointers are convertible to boolean (with the same
priority). So it is ambigious.

private:
Handle handle;
};

Shezan Baig wrote:

Tim Clacy wrote:

typedef struct tagHandle { }* Handle;
try instead:
struct Handle { SomeType* realHandle; };
bool eventIsSignalled(Handle hEvent);

struct Event
{
:
bool IsSignalled() const { return eventIsSignalled(*this); }

operator int () const { return IsSignalled(); }
operator Handle () const { return handle; }

ints *and* pointers are convertible to boolean (with the same
priority). So it is ambigious.

On Fri, 29 Apr 2005 18:45:08 +0200, "Tim Clacy"
<no*******@nospamphaseone.nospamdk> wrote:

Please illuminate; what operator of class ''Event'' will get matched for these
two cases [see Event outline later]:
[...]if (ev1 || ev2)
;

I would have thought ''operator int ()'' is the only obvious match, but my
compiler generates errors:

"ambiguous 3-way choice of conversion from ''struct Event'' in Boolean
context

All I''m trying to do is wrap an OS event in a class that can be treated like
a Boolean; can anyone explain what the ambiguity is and how it can be
resolved (preferable without casts)?

Shezan Baig summed up the ambiguity. As for what to do, I''d define
''Event::operator bool() const''.

Kanenas

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