get value of struct's member

I'm using a RecursiveASTVisitor and implementing its VisitCallExpr() method.
How can I get the value of struct's member?

bool VisitCallExpr(CallExpr *expr)
{
    for (int i=0;i<expr->getNumArgs();i++)
        {
            Expr* ex = expr->getArg(i);
            if (ex->getType()->isStructureType())
            {
                //get the value of struct's member
            }
        }
}

Thanks!

I'm using a RecursiveASTVisitor and implementing its VisitCallExpr()
method.
How can I get the value of struct's member?

bool VisitCallExpr(CallExpr *expr)
{
    for (int i=0;i<expr->getNumArgs();i++)
        {
            Expr* ex = expr->getArg(i);
            if (ex->getType()->isStructureType())
            {
                //get the value of struct's member
            }
        }
}

Thanks!

I'm not sure I understand what you're asking - in general the value of a
variable (or member of a struct) is only known at runtime.

Cheers,
/Manuel