c++ - Working Templates header file, not working anymore -

so, had 2 files:

• dfh_lib.h
• lib_test.cpp

the programs working 20-24 hours ago(i have executable file), decided exclude dfh_lib.cpp file empty (see below) , voila! it's giving me

declaration syntax error

on first line of top template function.

• i tried rearranging didn't help

this super annoying, i'm stuck turbo because of school , template based header file spend weeks building not compiling.

code

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this how dfh_lib.h file starts (excluding multi-line comment):

#ifndef dfh_lib_h #define dfh_lib_h  enum bool { false, true };  template <class t>    //error on line void addcolumn(t data, const int& width) {     cout<<setw(width)<<data<<" | "; } 

note: error comes while compiling dfh_lib.h

question

---

on adding dfh_lib.cpp file project, nothing this:

#ifndef _dfh_lib_cpp #define _dfh_lib_cpp  #include"dfh_lib.h"  #if !defined __fstream_h #include<fstream.h> #endif  #if !defined __iomanip_h #include<iomanip.h> #endif  #if !defined __conio_h #include<conio.h> #endif  #if !defined __stdio_h #include<stdio.h> #endif  #if !defined __string_h #include<string.h> #endif #endif 

everything worked fine! why happening? all headers written in dfh_lib.cpp included in lib_test.cpp prior including dfh_lib.h.

in opinion, dfh_lib.cpp file nothing seems important none less.

p.s. - apologize if duplicate, know this question exists couldn't relate situation. here, .cpp empty still required.

a quick mcve, put together:

utilization file:

#include<iostream.h> #include<conio.h> #include<iomanip.h> #include"fileio.h"  void fillspace(char ch, const int& width) {     cout<<setw(width)<<setfill(ch)<<"|"; } int record_id = 1; char char_member = 'a'; int int_member = 12; float float_member = 2.3;  void show_tablular() {     cout<<endl; addcolumn(record_id,7); addcolumn(char_member, 20); addcolumn(int_member, 11); addcolumn(float_member, 13); }  void main() {     clrscr();     cout<<endl; addcolumn("record", 7); addcolumn("char member", 20); addcolumn("int member", 11); addcolumn("float member", 13);     cout<<endl; addcolumn(" ", 7); addcolumn(" ", 20); addcolumn(" ", 11); addcolumn(" ", 13);     show_tablular();     cout<<endl; fillspace('_', 7+2); fillspace('_', 20+3); fillspace('_', 11+3); fillspace('_', 13+3);     cout<<setfill(' ');  //normalize cout based outputting format      getch(); } 

implementation file:

#include"fileio.h"  #if !defined __fstream_h #include<fstream.h> #endif  #if !defined __iomanip_h #include<iomanip.h> #endif  #if !defined __conio_h #include<conio.h> #endif  #if !defined __stdio_h #include<stdio.h> #endif  #if !defined __string_h #include<string.h> #endif 

header file:

#ifndef file_h #define file_h  enum bool { false, true };  template <class t> void addcolumn(t data, const int& width) {     cout<<setw(width)<<data<<" | "; }  #endif 

note: work if added project in same order top bottom otherwise above error encountered.