Functor to find a key in a vector

[John Doe]

Hi,

I have a vector of struct called ViewList defined like this :

class CViewMgr : public CSingleton<CVie wMgr>
{
friend class CSingleton<CVie wMgr>;

// Constructor
CViewMgr(): m_pCurView(NULL ) {}
CViewMgr(CViewM gr const&) {}
virtual ~CViewMgr(void) {}

protected:
CMobidjinnView m_MobidjinnView ;


public:
struct ViewInfo
{
ViewInfo(const GString& view, const CViewBase* a_pViewBase)
: m_viewname(view ), m_pView(a_pView Base)
{
}

GString m_viewname;
const CViewBase* m_pView;
};
typedef std::vector<Vie wInfoViewList;

void Init()
{
m_viewlist.push _back(ViewInfo( _T("SelectModul eView"), &m_MobidjinnVie w));
}

CViewBase* SwitchView(cons t GString& strViewName)
{
// I want to search in the ViewList an element
// with a m_viewname matching strViewName
CViewBase* pView = ??????????????? ??????????;
pView = find_if( m_viewlist.begi n(), m_viewlist.end( ),
... ) );

return NULL;
}

protected:
ViewList m_viewlist;
CViewBase* m_pCurView;

};


static inline CViewMgr& ViewMgr() { return *(CViewMgr::Get Instance()); }

and I would like to search my vector for a particular value matching the
m_viewname value.
How should I declare my functor ?

[Victor Bazarov]

Re: Functor to find a key in a vector

John Doe wrote:

Hi,
>
I have a vector of struct called ViewList defined like this :
>
class CViewMgr : public CSingleton<CVie wMgr>
{
friend class CSingleton<CVie wMgr>;
>
// Constructor
CViewMgr(): m_pCurView(NULL ) {}
CViewMgr(CViewM gr const&) {}
virtual ~CViewMgr(void) {}
>
protected:
CMobidjinnView m_MobidjinnView ;
>
>
public:
struct ViewInfo
{
ViewInfo(const GString& view, const CViewBase* a_pViewBase)
: m_viewname(view ), m_pView(a_pView Base)
{
}
>
GString m_viewname;
const CViewBase* m_pView;
};
typedef std::vector<Vie wInfoViewList;
>
void Init()
{
m_viewlist.push _back(ViewInfo( _T("SelectModul eView"),
&m_MobidjinnVie w));
}
>
CViewBase* SwitchView(cons t GString& strViewName)
{
// I want to search in the ViewList an element
// with a m_viewname matching strViewName
CViewBase* pView = ??????????????? ??????????;
pView = find_if( m_viewlist.begi n(), m_viewlist.end( ),
... ) );
>
return NULL;
}
>
protected:
ViewList m_viewlist;
CViewBase* m_pCurView;
>
};
>
>
static inline CViewMgr& ViewMgr() { return *(CViewMgr::Get Instance()); }
>
and I would like to search my vector for a particular value matching the
m_viewname value.
How should I declare my functor ?

Your functor needs to return 'true' when the value of the 'ViewInfo's
name coincides with the name the functor is given at its construction,
something like

struct EqualNameFuncto r {
GString nameToLookFor;
EqualNameFuncto r(GString const& n) : nameToLookFor(n ) {}
bool operator()(View Info const& vi) {
return vi.m_viewname == nameToLookFor;
}
};

and then call it like so

ViewList::itera tor found = find_if(m_viewl ist.begin(),
m_viewlist.end( ),
EqualNameFuncto r(strViewName)) ;
pView = found == m_viewlist.end( ) ? NULL : found->m_pView;

V
--
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[Alexey Stepanyan]

Re: Functor to find a key in a vector

On 30 ÏËÔ, 21:03, Victor Bazarov <v.Abaza...@com Acast.netwrote:

Your functor needs to return 'true' when the value of the 'ViewInfo's
name coincides with the name the functor is given at its construction,
something like
>
š š šstruct EqualNameFuncto r {
š š š š šGString nameToLookFor;
š š š š šEqualNameFunct or(GString const& n) : nameToLookFor(n ) {}
š š š š šbool operator()(View Info const& vi) {
š š š š š š šreturn vi.m_viewname == nameToLookFor;
š š š š š}
š š š};
>
and then call it like so
>
š šViewList::iter ator found = find_if(m_viewl ist.begin(),
š š š š š š š š š š š š š š š š š š š m_viewlist.end( ),
š š š š š š š š š š š š š š š š š š š EqualNameFuncto r(strViewName)) ;
š špView = found == m_viewlist.end( ) ? NULL : found->m_pView;
>
V
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Please remove capital 'A's when replying by e-mail
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>
- ðÏËÁÚÁÔØ ÃÉÔÉÒÕÅÍÙÊ ÔÅËÓÔ-

1) Wouldn't it be better to derive the pedicate from
std::unary_func tion<ViewInfo, bool-
at least it is a standard practice.
2) bool operator()(View Info const& vi) - should be const:
bool operator()(View Info const& vi) const
{
return vi.m_viewname == nameToLookFor;
}
3) I would also have GString nameToLookFor as a private member.

struct EqualNameFuncto r : public std::unary_func tion<ViewInfo, bool>
{
explicit EqualNameFuncto r(GString const& n) : nameToLookFor(n )
{} // pls note explicit ctor

bool operator()(View Info const& vi) const
{
return vi.m_viewname == nameToLookFor;
}

private:
GString nameToLookFor;
};