associative containers and templates

[Tracey]

hi

im a little stuck at the moment i wonder if someone can help

in recordtemplate.h i have the following template

template <class RecordType> class RecordClass
{
private:
AnsiString theFileName;

public:
//contructor
RecordClass(){};

//Destructor
~RecordClass(){};
};

in uTenant.h i have the class

//declare the tenant records
class TenantRecord : public RecordClass<AnsiString>
{
private:
public:
char FName[50];
char LName[50];
int Apartment;
};

and in uTenant.cpp :

//create an i/o file
fstream TenantFile;

// create a set of tenant records
set <TenantRecord, less<TenantRecord> > TTenants;

//create and iterator to the set of expense records
set <TenantRecord, less<TenantRecord> >::iterator teniter;

void __fastcall TfrmTenant::btnSaveClick(TObject *Sender)
{
TenantRecord thisrecord;

strcpy(thisrecord.FName,edtFName->Text.c_str());
strcpy(thisrecord.LName, edtLName->Text.c_str());
thisrecord.Apartment = StrToInt(edtApartment->Text);
TTenants.insert(thisrecord);
}

i am getting a compile error on the insert, which seems to be complaining about the &quot;less&quot; in the set.

[C++ Error] function.h(169): E2093 'operator<' not implemented in type 'TenantRecord' for arguments of the same type

what am i doing wrong.. I understand i need to use an iterator but have the same problem when i use it. I am just learning associative containers and templates and am very lost at this point. Pleeeeze help

 

[chipperMDW]

Looks like it wants you to overload operator< for your TenantRecord class.

The function object &quot;less&quot; uses that operator to compare its operands. When you instantiate the template, it generates some code that says &quot;a < b&quot;, where a and b are TenantRecord objects. Since there's no operator< that takes two TenantRecords, that expression doesn't work. That's what it's complaining about. You define an operator that takes those arguments to remedy the situation.