[gaza]

Hi All,
I have a function:

Pair<volScalarField> f() const
{
   Pair<volScalarField> myObj;
   // some modification of myObj

   return myObj;
}

Than in the code I have volScalarField object and I want to assign the

result of f() with it in this way:

volScalarField vsfObj;
vsfObj = f()[0];

however I got error:

error: no match for ‘operator=’ (operand types are ‘Foam::volScalarField {aka Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>}’ and ‘Foam::tmp<Foam::DimensionedField<double, Foam::volMesh> >’)

Can anyone know how to solve it?

[olesen]

Two things. Normally you'd want to construct the volScalarField with the argument instead of constructing empty and assigning after. But from you error message, it looks like your routine is not returning what it should. You need to check that.
For figuring these things if can be help to try assigning some thing really stupid, for example

// with your "f()" generator 
std::string junk = f().first();

The compiler errors will show the mismatch, from which you will see the types and also realise the problem is your return values (the righthand side)

[gaza]

Hi Mark,
Thank you for your reply. You are right my two sides are different.
To explain it better I give the line where error is and next the compiler error:

mCond_ = mDotAlphal()[0]*mesh.V();

where mCond is volScalarField and mDotAlphal() returns Pair<volScalarField>


And here is the error:

error: no match for ‘operator=’ (operand types are ‘Foam::volScalarField {aka Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>}’ and ‘Foam::tmp<Foam::DimensionedField<double, Foam::volMesh> >’)
   mCond_ = mDotAlphal()[0]*mesh.V();
                                   ^