Method OffsetFnInit

be/src/exprs/aggregate-functions-ir.cc:3649–3655

template <typename T>
void AggregateFunctions::OffsetFnInit(FunctionContext* ctx, T* dst) {
  DCHECK_EQ(ctx->GetNumArgs(), 3);
  DCHECK(ctx->IsArgConstant(1));
  DCHECK(ctx->IsArgConstant(2));
  DCHECK_EQ(ctx->GetArgType(0)->type, ctx->GetArgType(2)->type);
  *dst = *static_cast<T*>(ctx->GetConstantArg(2));
}

template <>
void AggregateFunctions::OffsetFnInit(FunctionContext* ctx, StringVal* dst) {