diff --git a/engine/ast.py b/engine/ast.py
index 7c02e2e..a4aaf70 100644
--- a/engine/ast.py
+++ b/engine/ast.py
@@ -15,6 +15,9 @@ class ColRef:
         self.order_pending = None # order_pending
         self.compound = compound # compound field (list as a field) 
         self.views = []
+        self.aux_columns = [] # columns for temperary calculations 
+        # e.g. order by, group by, filter by expressions
+        
         self.__arr__ = (cname, _ty, cobj, cnt, table, name, id)
     
     def reference(self):
@@ -90,6 +93,7 @@ class TableInfo:
             type_tags += '>'
             
             self.cxt.emit(f'auto& {base_name} = *(TableInfo{type_tags} *)(cxt->tables[{self.table_name}]);')
+        return self.cxt_name
     def refer_all(self):
         self.reference()
         for c in self.columns:
diff --git a/engine/ddl.py b/engine/ddl.py
index 130d54f..a13ba2c 100644
--- a/engine/ddl.py
+++ b/engine/ddl.py
@@ -88,6 +88,15 @@ class outfile(ast_node):
     def produce(self, node):
         out_table:TableInfo = self.parent.out_table
         filename = node['loc']['literal'] if 'loc' in node else node['literal']
+        sep = ',' if 'term' not in node else node['term']['literal']
+        self.context.headers.add('fstream')
+        cout_backup_buffer = 'stdout_' + base62uuid(4)
+        ofstream = 'ofstream_' + base62uuid(6)
+        
+        self.emit(f'auto {cout_backup_buffer} = cout.rdbuf();')
+        self.emit(f'auto {ofstream} = ofstream("{filename}");')
+        self.emit(f'cout.rdbuf({ofstream}.rdbuf());')
+        
         self.emit_no_ln(f"\"{filename}\"1:`csv@(+(")
         l_compound = False
         l_cols = ''
@@ -114,6 +123,10 @@ class outfile(ast_node):
         else:
             self.emit_no_ln(f'{l_keys}!+,/({ending(l_cols)})')
         self.emit('))')
-            
+        
+        self.emit(f'cout.rdbuf({cout_backup_buffer});')
+        self.emit(f'{ofstream}.close();')
+        
+        
 import sys
 include(sys.modules[__name__])
\ No newline at end of file
diff --git a/engine/expr.py b/engine/expr.py
index 0c8d380..91440e9 100644
--- a/engine/expr.py
+++ b/engine/expr.py
@@ -40,7 +40,7 @@ class expr(ast_node):
         'not' : '!'
     }
     
-    coumpound_generating_ops = ['mod', 'mins', 'maxs', 'sums'] + \
+    coumpound_generating_ops = ['avgs', 'mins', 'maxs', 'sums'] + \
        list( binary_ops.keys()) + list(compound_ops.keys()) + list(unary_ops.keys() )
 
     def __init__(self, parent, node, materialize_cols = True, abs_col = False):
diff --git a/engine/orderby.py b/engine/orderby.py
index ae410d4..7993fcd 100644
--- a/engine/orderby.py
+++ b/engine/orderby.py
@@ -16,43 +16,26 @@ class order_item:
         return ('' if self.order else '-') + f'({self.name})'
         
     def __str__(self):
-        return self.materialize()
+        return self.name
     def __repr__(self):
         return self.__str__()
 
-class orders:
-    def __init__(self, node, datasource):
-        self.order_items = []
-        self.materialized = False
-        self.view = None
-        self.node = node 
-        self.datasource = datasource
-        self.n_attrs = -1
-
-    def materialize(self):
-        if not self.materialized:
-            self.view = View(self.node.context, self.datasource, False)
-            keys = ';'.join([f'{o}' for o in self.order_items])
-            self.n_attrs = len(self.order_items)
-            self.node.emit(f"{self.view.name}: > +`j (({',' if self.n_attrs == 1 else ''}{keys}))")
-            self.materialized = True
-
-    def append(self, o):
-        self.order_items.append(o)
-
 class orderby(ast_node):
     name = '_orderby'
-    
+    def __init__(self, parent: "ast_node", node, context: Context = None):
+        self.col_list = []
+        super().__init__(parent, node, context)
     def init(self, _):
         self.datasource = self.parent.datasource
-        self.order = orders(self, self.datasource)
+        self.order = []
         self.view = ''
     def produce(self, node):
         if type(node) is not list:
             node = [node]
         for n in node:
             order =  not ('sort' in n and n['sort'] == 'desc')
+            col_id = self.datasource.columns_byname[n['value']].id
+            self.col_list.append(col_id if order else -col_id-1)
             self.order.append(order_item(n['value'], self, order))
-
-    def consume(self, _):
-        self.datasource.order.append(self.order)
\ No newline at end of file
+    def finialize(self, references):
+        self.order = [ o for o in self.order if o.name in references ]
\ No newline at end of file
diff --git a/engine/projection.py b/engine/projection.py
index 644deb4..204632e 100644
--- a/engine/projection.py
+++ b/engine/projection.py
@@ -14,6 +14,7 @@ class projection(ast_node):
         self.disp = disp
         self.outname = outname
         self.group_node = None
+        self.assumption = None
         self.where = None
         ast_node.__init__(self, parent, node, context)
     def init(self, _):
@@ -45,9 +46,8 @@ class projection(ast_node):
                     elif type(value) is str:
                         self.datasource = self.context.tables_byname[value]
                 if 'assumptions' in from_clause:
-                    for assumption in enlist(from_clause['assumptions']):
-                        orderby(self, assumption)
-
+                    self.assumption = orderby(self, enlist(from_clause['assumptions']))
+                    
             elif type(from_clause) is str:
                 self.datasource = self.context.tables_byname[from_clause]
             
@@ -83,7 +83,8 @@ class projection(ast_node):
         self.out_table = TableInfo('out_'+base62uuid(4), [], self.context)
         if 'outfile' in node:
             flatten = True
-            
+        
+        new_names = []
         for i, proj in enumerate(self.projections):
             cname = ''
             compound = False
@@ -92,12 +93,14 @@ class projection(ast_node):
                 if 'value' in proj:
                     e = proj['value']
                     sname = expr(self, e)._expr
-                    fname = expr.toCExpr(sname)
-                    absname = expr(self, e, abs_col=True)._expr
+                    fname = expr.toCExpr(sname) # fastest access method at innermost context
+                    absname = expr(self, e, abs_col=True)._expr # absolute name at function scope
                     compound = True
                     cexprs.append(fname)
-                    cname = ''.join([a if a in base62alp else '' for a in fname()])
-
+                    cname = e if type(e) is str else ''.join([a if a in base62alp else '' for a in expr.toCExpr(absname)()])
+                if 'name' in proj: # renaming column by AS keyword
+                    cname = proj['name']
+                    new_names.append(cname)
             compound = compound and has_groupby and self.datasource.rec not in self.group_node.referenced
             
             cols.append(ColRef(cname, expr.toCExpr(f'decays<decltype({absname})>')(0), self.out_table, 0, None, cname, i, compound=compound))
@@ -114,21 +117,17 @@ class projection(ast_node):
             self.where.finalize()
         
         has_orderby = 'orderby' in node
-
         if has_orderby:
             self.datasource = self.out_table
             self.context.datasource = self.out_table # discard current ds
             orderby_node = orderby(self, node['orderby'])
-            self.context.datasource.materialize_orderbys()
-            self.emit_no_ln(f"{f'{disp_varname}:+' if flatten else ''}(")
-            
-        if self.disp or has_orderby:
-            self.emit(f'print(*{self.out_table.cxt_name});')
-            
-        if has_orderby:
-            self.emit(f')[{orderby_node.view}]')
+            self.emit(f'auto {disp_varname} ={self.out_table.reference()}->order_by_view<{",".join([f"{c}" for c in orderby_node.col_list])}>();')
         else:
-            self.context.emit_flush()
+            disp_varname = f'*{self.out_table.cxt_name}'
+        if self.disp:
+            self.emit(f'print({disp_varname});')
+            
+
         if flatten:
             if len(self.projections) > 1 and not self.inv:
                 self.emit(f"{disp_varname}:+{disp_varname}")
diff --git a/out.cpp b/out.cpp
index 6867019..d91c898 100644
--- a/out.cpp
+++ b/out.cpp
@@ -1,8 +1,8 @@
 #include "csv.h"
-#include <unordered_map>
-#include "./server/libaquery.h"
 #include "./server/hasher.h"
+#include <unordered_map>
 #include "./server/aggregations.h"
+#include "./server/libaquery.h"
 
     extern "C" int __DLLEXPORT__ dllmain(Context* cxt) { 
         using namespace std;
@@ -17,40 +17,45 @@ test_a.init();
 test_b.init();
 test_c.init();
 test_d.init();
-io::CSVReader<4> csv_reader_6qlGpe("test.csv");
-csv_reader_6qlGpe.read_header(io::ignore_extra_column, "a","b","c","d");
-int tmp_39gHMkie;
-int tmp_190h2sZs;
-int tmp_4a8dDzSN;
-int tmp_3LAKxSmM;
-while(csv_reader_6qlGpe.read_row(tmp_39gHMkie,tmp_190h2sZs,tmp_4a8dDzSN,tmp_3LAKxSmM)) { 
+io::CSVReader<4> csv_reader_53LkPG("test.csv");
+csv_reader_53LkPG.read_header(io::ignore_extra_column, "a","b","c","d");
+int tmp_43xeYChp;
+int tmp_3Vnt4fLK;
+int tmp_1HKZwQBO;
+int tmp_6IwJuIpg;
+while(csv_reader_53LkPG.read_row(tmp_43xeYChp,tmp_3Vnt4fLK,tmp_1HKZwQBO,tmp_6IwJuIpg)) { 
 
-test_a.emplace_back(tmp_39gHMkie);
-test_b.emplace_back(tmp_190h2sZs);
-test_c.emplace_back(tmp_4a8dDzSN);
-test_d.emplace_back(tmp_3LAKxSmM);
+test_a.emplace_back(tmp_43xeYChp);
+test_b.emplace_back(tmp_3Vnt4fLK);
+test_c.emplace_back(tmp_1HKZwQBO);
+test_d.emplace_back(tmp_6IwJuIpg);
 }
-typedef record<decltype(test_a[0]),decltype(test_b[0]),decltype(test_d[0])> record_type2Te4GFo;
-unordered_map<record_type2Te4GFo, vector_type<uint32_t>, transTypes<record_type2Te4GFo, hasher>> g79JNXM8;
-for (uint32_t i5x = 0; i5x < test_a.size; ++i5x){
-g79JNXM8[forward_as_tuple(test_a[i5x],test_b[i5x],test_d[i5x])].emplace_back(i5x);
+typedef record<decltype(test_a[0]),decltype(test_b[0]),decltype(test_d[0])> record_type1CmZCvh;
+unordered_map<record_type1CmZCvh, vector_type<uint32_t>, transTypes<record_type1CmZCvh, hasher>> g6nov6MR;
+for (uint32_t i4I = 0; i4I < test_a.size; ++i4I){
+g6nov6MR[forward_as_tuple(test_a[i4I],test_b[i4I],test_d[i4I])].emplace_back(i4I);
 }
-auto out_5NL7 = new TableInfo<decays<decltype(sum(test_c[0]))>,decays<decltype(test_b[0])>,decays<decltype(test_d[0])>>("out_5NL7", 3);
-cxt->tables.insert({"out_5NL7", out_5NL7});
-auto& out_5NL7_sumtestc = *(ColRef<decays<decltype(sum(test_c[0]))>> *)(&out_5NL7->colrefs[0]);
-auto& out_5NL7_get1None = *(ColRef<decays<decltype(test_b[0])>> *)(&out_5NL7->colrefs[1]);
-auto& out_5NL7_get2None = *(ColRef<decays<decltype(test_d[0])>> *)(&out_5NL7->colrefs[2]);
-out_5NL7_sumtestc.init();
-out_5NL7_get1None.init();
-out_5NL7_get2None.init();
-for(auto& i4l : g79JNXM8) {
-auto &key_ADPihOU = i4l.first;
-auto &val_7LsrkDP = i4l.second;
-out_5NL7_sumtestc.emplace_back(sum(test_c[val_7LsrkDP]));
-out_5NL7_get1None.emplace_back(get<1>(key_ADPihOU));
-out_5NL7_get2None.emplace_back(get<2>(key_ADPihOU));
+auto out_684r = new TableInfo<decays<decltype(sum(test_c[0]))>,decays<decltype(test_b[0])>,decays<decltype(test_d[0])>>("out_684r", 3);
+cxt->tables.insert({"out_684r", out_684r});
+auto& out_684r_sumtestc = *(ColRef<decays<decltype(sum(test_c[0]))>> *)(&out_684r->colrefs[0]);
+auto& out_684r_b = *(ColRef<decays<decltype(test_b[0])>> *)(&out_684r->colrefs[1]);
+auto& out_684r_d = *(ColRef<decays<decltype(test_d[0])>> *)(&out_684r->colrefs[2]);
+out_684r_sumtestc.init();
+out_684r_b.init();
+out_684r_d.init();
+for(auto& i3d : g6nov6MR) {
+auto &key_1TaM8D7 = i3d.first;
+auto &val_129np3x = i3d.second;
+out_684r_sumtestc.emplace_back(sum(test_c[val_129np3x]));
+out_684r_b.emplace_back(get<1>(key_1TaM8D7));
+out_684r_d.emplace_back(get<2>(key_1TaM8D7));
 }
-print(*out_5NL7);
-
+auto d2X3bP6l =out_684r->order_by_view<-3,1>();
+puts("a");
+print(*(out_684r->order_by<-3,1>()));
+puts("b");
+print(out_684r->order_by_view<-3,1>());
+puts("e");
+print(*out_684r);
 return 0;
 }
\ No newline at end of file
diff --git a/q1.sql b/q1.sql
index bd6d5fd..360dc2f 100644
--- a/q1.sql
+++ b/q1.sql
@@ -7,4 +7,4 @@ FIELDS TERMINATED BY ","
 SELECT sum(c), b, d
 FROM test
 group by a,b,d
--- order by d DESC, b ASC
+order by d DESC, b ASC
diff --git a/server/io.h b/server/io.h
new file mode 100644
index 0000000..ad7835b
--- /dev/null
+++ b/server/io.h
@@ -0,0 +1,15 @@
+#pragma once
+#include "types.h"
+#include <cstdio>
+#include <string>
+#include <cstdio>
+#include <string>
+template <class ...Types>
+std::string generate_printf_string(const char* sep = " ", const char* end = "\n") {
+	std::string str;
+	(void)std::initializer_list<int>{
+		(str += types::printf_str[types::Types<Types>::getType()], str += sep, 0)...
+	};
+	str += end;
+	return str;
+}
diff --git a/server/priority_vector.hpp b/server/priority_vector.hpp
new file mode 100644
index 0000000..f1c7d6f
--- /dev/null
+++ b/server/priority_vector.hpp
@@ -0,0 +1,19 @@
+#pragma once
+#include "vector_type.hpp"
+#include <algorithm>
+#include <stdint.h>
+template <class Comparator, typename T = uint32_t>
+class priority_vector : public vector_type<T> {
+	const Comparator comp;
+public:
+	priority_vector(Comparator comp = std::less<T>{}) : 
+		comp(comp), vector_type<T>(0) {}
+	void emplace_back(T val) {
+		vector_type<T>::emplace_back(val);
+		std::push_heap(container, container + size, comp);
+	}
+	void pop_back() {
+		std::pop_heap(container, container + size, comp);
+		--size;
+	}
+}; 
\ No newline at end of file
diff --git a/server/server.cpp b/server/server.cpp
index 5ff0738..fe06af1 100644
--- a/server/server.cpp
+++ b/server/server.cpp
@@ -75,6 +75,7 @@ int main(int argc, char** argv) {
     shm.FreeMemoryMap();
     return 0;
 }
+#include "utils.h"
 int _main()
 {
 
@@ -83,6 +84,7 @@ int _main()
     //t.emplace_back(2);
     //print(t);
     //return 0;
+    puts(cpp_17 ?"true":"false");
     void* handle = dlopen("dll.so", RTLD_LAZY);
     printf("handle: %x\n", handle);
     Context* cxt = new Context();
@@ -96,7 +98,8 @@ int _main()
         }
         dlclose(handle);
     }
-
+    static_assert(std::is_same_v<decltype(fill_integer_array<5, 1>()), std::integer_sequence<bool, 1,1,1,1,1>>, "");
     return 0;
+    
 }
 
diff --git a/server/server.vcxproj b/server/server.vcxproj
index 221f1dd..03f1f79 100644
--- a/server/server.vcxproj
+++ b/server/server.vcxproj
@@ -168,6 +168,7 @@
     <ClInclude Include="gc.hpp" />
     <ClInclude Include="hasher.h" />
     <ClInclude Include="libaquery.h" />
+    <ClInclude Include="priority_vector.hpp" />
     <ClInclude Include="table.h" />
     <ClInclude Include="types.h" />
     <ClInclude Include="utils.h" />
@@ -175,10 +176,4 @@
     <ClInclude Include="winhelper.h" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
-  <ImportGroup Label="ExtensionTargets" />
-  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
-    <PropertyGroup>
-      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
-    </PropertyGroup>
-  </Target>
 </Project>
\ No newline at end of file
diff --git a/server/table.h b/server/table.h
index abdeb06..ffbe96b 100644
--- a/server/table.h
+++ b/server/table.h
@@ -1,3 +1,5 @@
+// TODO: Replace `cout, printf` with sprintf&fputs and custom buffers
+
 #ifndef _TABLE_H
 #define _TABLE_H
 
@@ -85,13 +87,31 @@ inline ColRef<T> ColRef<_Ty>::scast()
 	return *(ColRef<T> *)this;
 }
 using uColRef = ColRef<void>;
+
+template<class ...Types> struct TableInfo;
+template<class ...Types> struct TableView;
+
+template <long long _Index, bool order = true, class... _Types>
+constexpr inline auto& get(const TableInfo<_Types...>& table) noexcept {
+	if constexpr (order)
+		return *(ColRef<std::tuple_element_t<_Index, std::tuple<_Types...>>> *) & (table.colrefs[_Index]);
+	else 
+		return *(ColRef<std::tuple_element_t<-1-_Index, std::tuple<_Types...>>> *) & (table.colrefs[-1-_Index]);
+}
+
+template <long long _Index, class... _Types>
+constexpr inline ColRef<std::tuple_element_t<_Index, std::tuple<_Types...>>>& get(const TableView<_Types...>& table) noexcept {
+	return *(ColRef<std::tuple_element_t<_Index, std::tuple<_Types...>>> *) & (table.info.colrefs[_Index]);
+}
+template<class ...Types>
+struct TableView;
 template<class ...Types>
 struct TableInfo {
 	const char* name;
 	ColRef<void>* colrefs;
 	uint32_t n_cols;
-	void print(const char* __restrict sep, const char* __restrict end) const;
 	typedef std::tuple<Types...> tuple_type;
+	void print(const char* __restrict sep, const char* __restrict end) const;
 	template <size_t j = 0>
 	typename std::enable_if<j == sizeof...(Types) - 1, void>::type print_impl(const uint32_t& i, const char* __restrict sep = " ") const;
 	template <size_t j = 0>
@@ -103,46 +123,60 @@ struct TableInfo {
 	template <size_t ...Idxs>
 	using getRecordType = typename GetTypes<Idxs...>::type;
 	TableInfo(const char* name, uint32_t n_cols);
-	//template<size_t ...Idxs = Types...>
-	//struct Iterator_t {
-	//	uint32_t val;
-	//	const TableInfo* info;
-	//	constexpr Iterator_t(const uint32_t* val, const TableInfo* info) noexcept : val(val), info(info) {}
-	//	getRecordType<Idxs...> operator*() {
-	//		return getRecordType<Idxs...>(info->colrefs[Idxs].operator[](*val)...);
-	//	}
-	//	bool operator != (const Iterator_t& rhs) { return rhs.val != val; }
-	//	Iterator_t& operator++ () {
-	//		++val;
-	//		return *this;
-	//	}
-	//	Iterator_t operator++ (int) {
-	//		Iterator_t tmp = *this;
-	//		++val;
-	//		return tmp;
-	//	}
-	//};
-	//template<size_t ...Idxs = Types...>
-	//Iterator_t<Idxs...> begin() const {
-	//	
-	//}
-	//template<size_t ...Idxs = Types...>
-	//Iterator_t<Idxs...> end() const {
-	//	
-	//}
-	//
-	//template<int ...Cols, bool ...ord>
-	//order_by() {
-	//	vector_type<uint32_t> order(colrefs[0].size);
-	//	std::sort(this->begin<Cols>)
-	//}
+	template <int prog = 0>
+	inline void materialize(const vector_type<uint32_t>& idxs, TableInfo<Types...>* tbl = nullptr) { // inplace materialize
+		if constexpr(prog == 0) tbl = 0 ? this : tbl;
+		if constexpr (prog == sizeof...(Types)) return;
+		else {
+			auto& col = get<prog>(*this);
+			auto new_col = decays<decltype(col)>{idxs.size};
+			for(uint32_t i = 0; i < idxs.size; ++i)
+				new_col[i] = col[idxs[i]];
+			get<prog>(*tbl) = new_col;
+			materialize<prog + 1>();
+		}
+	}
+	inline TableInfo<Types...>* materialize_copy(const vector_type<uint32_t>& idxs) { 
+		auto tbl = new TableInfo<Types...>(this->name, sizeof...(Types));
+		materialize<0>(idxs, tbl);
+		return tbl;
+	}
+	template<int ...cols>
+	inline vector_type<uint32_t>* order_by() {
+		vector_type<uint32_t>* ord = new vector_type<uint32_t>(colrefs[0].size);
+		for (uint32_t i = 0; i < colrefs[0].size; ++i)
+			(*ord)[i] = i;
+		std::sort(ord->begin(), ord->end(), [this](const uint32_t& lhs, const uint32_t& rhs) {
+			return
+				std::forward_as_tuple((cols >= 0 ? get<cols, (cols >= 0)>(*this)[lhs] : -get<cols, (cols >= 0)>(*this)[lhs]) ...)
+				<
+				std::forward_as_tuple((cols >= 0 ? get<cols, (cols >= 0)>(*this)[rhs] : -get<cols, (cols >= 0)>(*this)[rhs]) ...);
+			});
+		return ord;
+	}
+	template <int ...cols>
+	auto order_by_view () {
+		return TableView<Types...>(order_by<cols...>(), *this);
+	}
+	
 };
 
-template <size_t _Index, class... _Types>
-constexpr inline ColRef<std::tuple_element_t<_Index, std::tuple<_Types...>>>& get(const TableInfo<_Types...>& table) noexcept {
-	return *(ColRef<std::tuple_element_t<_Index, std::tuple<_Types...>>> *) & (table.colrefs[_Index]);
-}
 
+template<class ...Types>
+struct TableView {
+	const vector_type<uint32_t>* idxs;
+	const TableInfo<Types...>& info;
+	constexpr TableView(const vector_type<uint32_t>* idxs, const TableInfo<Types...>& info) noexcept : idxs(idxs), info(info) {}
+	void print(const char* __restrict sep, const char* __restrict end) const;
+	template <size_t j = 0>
+	typename std::enable_if<j == sizeof...(Types) - 1, void>::type print_impl(const uint32_t& i, const char* __restrict sep = " ") const;
+	template <size_t j = 0>
+	typename std::enable_if < j < sizeof...(Types) - 1, void>::type print_impl(const uint32_t& i, const char* __restrict sep = " ") const;
+	
+	~TableView() {
+		delete idxs;
+	}
+};
 template <class T>
 constexpr static inline bool is_vector(const ColRef<T>&) {
 	return true;
@@ -159,7 +193,32 @@ template<class ...Types>
 TableInfo<Types...>::TableInfo(const char* name, uint32_t n_cols) : name(name), n_cols(n_cols) {
 	this->colrefs = (ColRef<void>*)malloc(sizeof(ColRef<void>) * n_cols);
 }
+template <class ...Types>
+template <size_t j>
+inline typename std::enable_if<j == sizeof...(Types) - 1, void>::type
+TableView<Types ...>::print_impl(const uint32_t& i, const char* __restrict sep) const {
+	std::cout << (get<j>(*this))[(*idxs)[i]];
+}
+
+template<class ...Types>
+template<size_t j>
+inline typename std::enable_if < j < sizeof...(Types) - 1, void>::type
+	TableView<Types...>::print_impl(const uint32_t& i, const char* __restrict sep) const
+{
+	std::cout << (get<j>(*this))[(*idxs)[i]] << sep;
+	print_impl<j + 1>(i, sep);
+}
 
+template<class ...Types>
+inline void TableView<Types...>::print(const char* __restrict sep, const char* __restrict end) const {
+	int n_rows = 0;
+	if (info.colrefs[0].size > 0)
+		n_rows = info.colrefs[0].size;
+	for (int i = 0; i < n_rows; ++i) {
+		print_impl(i);
+		std::cout << end;
+	}
+}
 template <class ...Types>
 template <size_t j>
 inline typename std::enable_if<j == sizeof...(Types) - 1, void>::type
@@ -247,17 +306,24 @@ template <class ...Types>
 void print(const TableInfo<Types...>& v, const char* delimiter = " ", const char* endline = "\n") {
 	v.print(delimiter, endline);
 }
+template <class ...Types>
+void print(const TableView<Types...>& v, const char* delimiter = " ", const char* endline = "\n") {
+	v.print(delimiter, endline);
+}
 template <class T>
 void print(const T& v, const char* delimiter = " ") {
-	printf(types::printf_str[types::Types<T>::getType()], v);
+	std::cout<< v;
+	// printf(types::printf_str[types::Types<T>::getType()], v);
 }
 template <class T>
 void inline print_impl(const T& v, const char* delimiter, const char* endline) {
 	for (const auto& vi : v) {
 		print(vi);
-		printf("%s", delimiter);
+		std::cout << delimiter;
+		// printf("%s", delimiter);
 	}
-	printf("%s", endline);
+	std::cout << endline;
+	//printf("%s", endline);
 }
 
 template <class T, template<typename> class VT>
diff --git a/server/types.h b/server/types.h
index 6d6c4b9..11c397b 100644
--- a/server/types.h
+++ b/server/types.h
@@ -118,6 +118,16 @@ struct decayS <T<Types...>>{
 	using type = T<typename std::decay<Types>::type ...>;
 };
 template <class T>
-using decays = typename decayS<T>::type;
+using decays = typename decayS<typename std::decay<T>::type>::type;
+template <class T>
+using decay_inner = typename decayS<T>::type;
+
+template <int n, bool v = 1, bool ...vals>
+auto fill_integer_array() {
+	if constexpr (n == 0)
+		return std::integer_sequence<bool, vals...>{};
+	else
+		return fill_integer_array<n - 1, v, v, vals...>();
+};
 
 #endif // !_TYPES_H
diff --git a/server/utils.h b/server/utils.h
index 0e1a4ef..cb58974 100644
--- a/server/utils.h
+++ b/server/utils.h
@@ -1,18 +1,16 @@
 #pragma once
 #include <string>
 #include <ctime>
-
-template<int cnt, int begin = 0, int interval = 1>
-struct const_range {
-	int arr[cnt];
-	constexpr const_range() {
-		for (int i = begin, n = 0; n < cnt; ++n, i += interval)
-			arr[n] = i;
-	}
-	const int* begin() const {
-		return arr;
-	}
-	const int* end() const {
-		return arr + cnt;
-	}
-};
\ No newline at end of file
+#if ((defined(_MSVC_LANG) && _MSVC_LANG >= 201703L) || __cplusplus >= 201703L)
+constexpr static bool cpp_17 = true;
+#else
+constexpr static bool cpp_17 = false;
+#endif
+template <class T>
+inline const char* str(const T& v) {
+	return "";
+}
+template <>
+inline const char* str(const bool& v) {
+	return v ? "true" : "false";
+}
\ No newline at end of file
diff --git a/server/vector_type.hpp b/server/vector_type.hpp
index 05fe03c..2ec4cd6 100644
--- a/server/vector_type.hpp
+++ b/server/vector_type.hpp
@@ -22,7 +22,7 @@
 template <typename _Ty>
 class vector_type {
 public:
-	void inline _copy(vector_type<_Ty>& vt) {
+	void inline _copy(const vector_type<_Ty>& vt) {
 		this->size = vt.size;
 		this->capacity = vt.capacity;
 		this->container = (_Ty*)malloc(size * sizeof(_Ty));
@@ -30,6 +30,8 @@ public:
 		memcpy(container, vt.container, sizeof(_Ty) * size);
 	}
 	void inline _move(vector_type<_Ty>&& vt) {
+		if (capacity > 0) free(container);
+		
 		this->size = vt.size;
 		this->capacity = vt.capacity;
 		this->container = vt.container;
@@ -52,7 +54,7 @@ public:
 		}
 	}
 	constexpr vector_type() noexcept : size(0), capacity(0), container(0) {};
-	constexpr vector_type(vector_type<_Ty>& vt) noexcept {
+	constexpr vector_type(const vector_type<_Ty>& vt) noexcept {
 		_copy(vt);
 	}
 	constexpr vector_type(vector_type<_Ty>&& vt) noexcept {
@@ -67,7 +69,7 @@ public:
 		container[0] = vt;
 		return *this;
 	}
-	vector_type<_Ty> operator =(vector_type<_Ty>& vt) {
+	vector_type<_Ty> operator =(const vector_type<_Ty>& vt) {
 		_copy(vt);
 		return *this;
 	}