diff --git a/include/builtin.h b/include/builtin.h
index 05a60e8..17d0b69 100644
--- a/include/builtin.h
+++ b/include/builtin.h
@@ -1,9 +1,92 @@
+#include <cmath>
 #include "object.h"
 
-ObjectBase* Arifm_Add(const ObjectList* input);
-ObjectBase* Arifm_Sub(const ObjectList* input);
-ObjectBase* Arifm_Mul(const ObjectList* input);
-ObjectBase* Arifm_Div(const ObjectList* input);
-ObjectBase* Arifm_Pow(const ObjectList* input);
-ObjectBase* Arifm_Neg(const ObjectList* input);
-ObjectBase* Arifm_Pos(const ObjectList* input);
+template<class O>
+struct Valued
+{
+ double operator ()(const O* q, bool* isok) {return q->Value();}
+};
+
+template<>
+struct Valued<ObjectString>
+{
+ double operator ()(const ObjectString* q, bool* isok) {double d=0; *isok=str2double(q->Value(),&d); return d;}
+};
+
+template<class O>
+struct Valuei
+{
+ int64_t operator ()(const O* q, bool* isok) {return q->Value();}
+};
+
+template<>
+struct Valuei<ObjectString>
+{
+ int64_t operator ()(const ObjectString* q, bool* isok) {int64_t i=0; *isok=str2int(q->Value(),&i); return i;}
+};
+
+
+template<class T> class OpAdd {public: static T V(T a1, T a2) {return a1+a2;}};
+template<class T> class OpSub {public: static T V(T a1, T a2) {return a1-a2;}};
+template<class T> class OpMul {public: static T V(T a1, T a2) {return a1*a2;}};
+template<class T> class OpDiv {public: static T V(T a1, T a2) {return a1/a2;}};
+template<class T> class OpPow {public: static T V(T a1, T a2) {return pow(a1,a2);}};
+template<class T> class OpNeg {public: static T V(T a) {return -a;}};
+template<class T> class OpPos {public: static T V(T a) {return +a;}};
+
+template<template<typename> class Op, bool intArifm=true>
+ObjectBase* Arifm2(const ObjectList* input)
+{
+ if(input->Size()!=2) return 0;
+ const ObjectBase *arg1=input->At(0),*arg2=input->At(1);
+ OBTypeM<Valuei,ObjectInt,ObjectString> i1(arg1), i2(arg2);
+ OBTypeM<Valued,ObjectReal,ObjectInt,ObjectString> r1(arg1), r2(arg2);
+ bool isok;
+
+ // Integer arifmetic
+ isok=true;
+ if(i1 && i2 && intArifm)
+ {
+  int64_t v1=i1(&isok),v2=i2(&isok);
+  if(isok) return new ObjectInt(Op<int64_t>::V(v1,v2));
+ }
+
+ // Real arifmetic
+ isok=true;
+ if(r1 && r2)
+ {
+  double v1=r1(&isok),v2=r2(&isok);
+  if(isok) return new ObjectReal(Op<double>::V(v1,v2));
+ }
+
+ return 0;
+}
+
+
+template<template<typename> class Op, bool intArifm=true>
+ObjectBase* Arifm1(const ObjectList* input)
+{
+ if(input->Size()!=1) return 0;
+ const ObjectBase *arg=input->At(0);
+ OBTypeM<Valuei,ObjectInt,ObjectString> i(arg);
+ OBTypeM<Valued,ObjectReal,ObjectString> r(arg);
+ bool isok;
+
+ // Integer arifmetic
+ isok=true;
+ if(i && intArifm)
+ {
+  int64_t v=i(&isok);
+  if(isok) return new ObjectInt(Op<int64_t>::V(v));
+ }
+
+ // Real arifmetic
+ isok=true;
+ if(r)
+ {
+  double v=r(&isok);
+  if(isok) return new ObjectReal(Op<double>::V(v));
+ }
+
+ return 0;
+}
diff --git a/src/builtin.cpp b/src/builtin.cpp
deleted file mode 100644
index adabd3d..0000000
--- a/src/builtin.cpp
+++ /dev/null
@@ -1,123 +0,0 @@
-#include <math.h>
-#include "object.h"
-
-class Val
-{
- double v;
- public:
- Val() = delete;
- Val(Val&&) = delete;
- Val(Val&) = delete;
- Val(const OBType<ObjectInt>& i, const OBType<ObjectReal>& r) {v=r?r->Value():i->Value();}
- Val(const OBType<ObjectReal>& r, const OBType<ObjectInt>& i) {v=r?r->Value():i->Value();}
- operator double() const {return v;}
-};
-
-ObjectBase* Arifm_Add(const ObjectList* input)
-{
- if(input->Size()!=2) return 0;
- const ObjectBase *arg1=input->At(0),*arg2=input->At(1);
- OBType<ObjectInt> i1(arg1), i2(arg2);
- OBType<ObjectReal> r1(arg1), r2(arg2);
-
- if( !(i1 || r1) || !(i2 || r2) ) return 0;
-
- // Integer arifmetic
- if(i1 && i2) return new ObjectInt(i1->Value()+i2->Value());
- // Real arifmetic
- return new ObjectReal(Val(i1,r1)+Val(i2,r2));
-}
-
-
-ObjectBase* Arifm_Sub(const ObjectList* input)
-{
- if(input->Size()!=2) return 0;
- const ObjectBase *arg1=input->At(0),*arg2=input->At(1);
- OBType<ObjectInt> i1(arg1), i2(arg2);
- OBType<ObjectReal> r1(arg1), r2(arg2);
-
- if( !(i1 || r1) || !(i2 || r2) ) return 0;
-
- // Integer arifmetic
- if(i1 && i2) return new ObjectInt(i1->Value()-i2->Value());
- // Real arifmetic
- return new ObjectReal(Val(i1,r1)-Val(i2,r2));
-}
-
-
-ObjectBase* Arifm_Mul(const ObjectList* input)
-{
- if(input->Size()!=2) return 0;
- const ObjectBase *arg1=input->At(0),*arg2=input->At(1);
- OBType<ObjectInt> i1(arg1), i2(arg2);
- OBType<ObjectReal> r1(arg1), r2(arg2);
-
- if( !(i1 || r1) || !(i2 || r2) ) return 0;
-
- // Integer arifmetic
- if(i1 && i2) return new ObjectInt(i1->Value()*i2->Value());
- // Real arifmetic
- return new ObjectReal(Val(i1,r1)*Val(i2,r2));
-}
-
-
-ObjectBase* Arifm_Div(const ObjectList* input)
-{
- if(input->Size()!=2) return 0;
- const ObjectBase *arg1=input->At(0),*arg2=input->At(1);
- OBType<ObjectInt> i1(arg1), i2(arg2);
- OBType<ObjectReal> r1(arg1), r2(arg2);
-
- if( !(i1 || r1) || !(i2 || r2) ) return 0;
-
- // Integer arifmetic
- if(i1 && i2) return new ObjectInt(i1->Value()/i2->Value());
- // Real arifmetic
- return new ObjectReal(Val(i1,r1)/Val(i2,r2));
-}
-
-
-ObjectBase* Arifm_Pow(const ObjectList* input)
-{
- if(input->Size()!=2) return 0;
- const ObjectBase *arg1=input->At(0),*arg2=input->At(1);
- OBType<ObjectInt> i1(arg1), i2(arg2);
- OBType<ObjectReal> r1(arg1), r2(arg2);
-
- if( !(i1 || r1) || !(i2 || r2) ) return 0;
-
- // Only real arifmetic
- return new ObjectReal(pow(Val(i1,r1),Val(i2,r2)));
-}
-
-
-ObjectBase* Arifm_Neg(const ObjectList* input)
-{
- if(input->Size()!=1) return 0;
- const ObjectBase *arg=input->At(0);
- OBType<ObjectInt> i(arg);
- OBType<ObjectReal> r(arg);
-
- // Integer arifmetic
- if(i) return new ObjectInt(-i->Value());
- // Real arifmetic
- if(r) return new ObjectReal(-r->Value());
-
- return 0;
-}
-
-
-ObjectBase* Arifm_Pos(const ObjectList* input)
-{
- if(input->Size()!=1) return 0;
- const ObjectBase *arg=input->At(0);
- OBType<ObjectInt> i(arg);
- OBType<ObjectReal> r(arg);
-
- // Integer arifmetic
- if(i) return new ObjectInt(i->Value());
- // Real arifmetic
- if(r) return new ObjectReal(r->Value());
-
- return 0;
-}
diff --git a/src/init.cpp b/src/init.cpp
index 562380e..0701819 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -134,13 +134,13 @@ int ParseOptions(int argc, char** argv, struct program_options& options)
 
 int RegisterBuiltinFunctions()
 {
- RegisterFunction("ADD",Arifm_Add);
- RegisterFunction("SUB",Arifm_Sub);
- RegisterFunction("MUL",Arifm_Mul);
- RegisterFunction("DIV",Arifm_Div);
- RegisterFunction("POW",Arifm_Pow);
- RegisterFunction("POS",Arifm_Pos);
- RegisterFunction("NEG",Arifm_Neg);
+ RegisterFunction("ADD",Arifm2<OpAdd>);
+ RegisterFunction("SUB",Arifm2<OpSub>);
+ RegisterFunction("MUL",Arifm2<OpMul>);
+ RegisterFunction("DIV",Arifm2<OpDiv>);
+ RegisterFunction("POW",Arifm2<OpPow,false>);
+ RegisterFunction("NEG",Arifm1<OpNeg>);
+ RegisterFunction("POS",Arifm1<OpPos>);
 
  RegisterFunction("GET",Get<ObjectList>);
  RegisterFunction("GET",Get<ObjectPair>);