_variant_t

[Eric Kaplan]

Why I got error for following code:
vtValue == VT_NULL

1>d:\trash4\database\database.cpp(156) : error C2593: 'operator ==' is
ambiguous

======================
bool Table::Get(char* FieldName,int& FieldValue){

_variant_t vtValue;
vtValue = m_Rec->Fields->GetItem(FieldName)->GetValue();
if (vtValue == VT_NULL ){
FieldValue = 0;
} else {
FieldValue=vtValue.date;
}

}

 

[SvenC]

Hi Eric,

Why I got error for following code:
vtValue == VT_NULL

you want vtValue.vt == VT_NULL

 

[Giovanni Dicanio]

Why I got error for following code:
vtValue == VT_NULL

1>d:\trash4\database\database.cpp(156) : error C2593: 'operator ==' is
ambiguous

======================
bool Table::Get(char* FieldName,int& FieldValue){

_variant_t vtValue;
vtValue = m_Rec->Fields->GetItem(FieldName)->GetValue();
if (vtValue == VT_NULL ){

You may correct your code like this:

if ( vtValue.vt == VT_NULL )
...

_variant_t derives from VARIANT (i.e.: from struct tagVARIANT), so you can
access the 'VARTYPE vt' field using dot notation (.vt), and compare its
value with VT_NULL.

Giovanni