friending istream operator with class - c++

hello i'm trying to overload my operator >> to my class but i ecnouter an error in eclipse.
code:
friend istream& operator>>(const istream& is, const RAngle& ra){
return is >> ra.x >> ra.y;
}
code2:
friend istream& operator>>(const istream& is, const RAngle& ra)
{
is >> ra.x;
is >> ra.y;
return is
}
Both crash and i don't know why, please help.
EDIT:
ra.x & ra.y are both 2 private ints of my class;
Full error:
error:
..\/rightangle.h: In function 'std::istream& operator>>(std::istream&, const RAngle&)':
..\/rightangle.h:65:12: error: ambiguous overload for 'operator>>' in 'is >> ra.RAngle::x'
..\/rightangle.h:65:12: note: candidates are:
c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include/c++/istream:122:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__istream_type& (*)(std::basic_istream<_CharT, _Traits>::__istream_type&)) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>] <near match>
c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include/c++/istream:122:7: note: no known conversion for argument 1 from 'const int' to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&) {aka std::basic_istream<char>& (*)(std::basic_istream<char>&)}'
c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include/c++/istream:126:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__ios_type& (*)(std::basic_istream<_CharT, _Traits>::__ios_type&)) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>, std::basic_istream<_CharT, _Traits>::__ios_type = std::basic_ios<char>] <near match>
c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include/c++/istream:126:7: note: no known conversion for argument 1 from 'const int' to 'std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&) {aka std::basic_ios<char>& (*)(std::basic_ios<char>&)}'
c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include/c++/istream:133:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::ios_base& (*)(std::ios_base&)) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>] <near match>
c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include/c++/istream:133:7: note: no known conversion for argument 1 from 'const int' to 'std::ios_base& (*)(std::ios_base&)'
c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include/c++/istream:241:7: note: std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__streambuf_type*) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__streambuf_type = std::basic_streambuf<char>] <near match>
c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include/c++/istream:241:7: note: no known conversion for argument 1 from 'const int' to 'std::basic_istream<char>::__streambuf_type* {aka std::basic_streambuf<char>*}'
..\/rightangle.h:66:12: error: ambiguous overload for 'operator>>' in 'is >> ra.RAngle::y'
..\/rightangle.h:66:12: note: candidates are:
c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include/c++/istream:122:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__istream_type& (*)(std::basic_istream<_CharT, _Traits>::__istream_type&)) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>] <near match>
c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include/c++/istream:122:7: note: no known conversion for argument 1 from 'const int' to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&) {aka std::basic_istream<char>& (*)(std::basic_istream<char>&)}'
c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include/c++/istream:126:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__ios_type& (*)(std::basic_istream<_CharT, _Traits>::__ios_type&)) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>, std::basic_istream<_CharT, _Traits>::__ios_type = std::basic_ios<char>] <near match>
c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include/c++/istream:126:7: note: no known conversion for argument 1 from 'const int' to 'std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&) {aka std::basic_ios<char>& (*)(std::basic_ios<char>&)}'
c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include/c++/istream:133:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::ios_base& (*)(std::ios_base&)) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>] <near match>
c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include/c++/istream:133:7: note: no known conversion for argument 1 from 'const int' to 'std::ios_base& (*)(std::ios_base&)'
c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include/c++/istream:241:7: note: std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__streambuf_type*) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__streambuf_type = std::basic_streambuf<char>] <near match>
c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include/c++/istream:241:7: note: no known conversion for argument 1 from 'const int' to 'std::basic_istream<char>::__streambuf_type* {aka std::basic_streambuf<char>*}''

Since operator>> is going to modify the parameters you pass to it, they cannot be references to const, so what you want is something like:
friend std::istream &operator>>(std::istream &is, RAngle &ra) {
return is >> ra.x >> ra.y;
}
Note that almost any I/O operation also (at least potentially) changes the state of the stream, so you (nearly?) always want to pass stream parameters by non-const reference.

One problem is in the signature of the operator:
friend istream& operator>>(const istream& is, const RAngle& ra){
// ^^^^^ ^^^^^
return is >> ra.x >> ra.y;
}
If the arguments are const you will not be able to modify them. As of the error messages, they seem to indicate that the compiler is failing to find an appropriate overload for is >> ra.x and is >> ra.y. This might be related to the previous issue (cannot find an overload that takes a const-lvalue) or not, depending on what the types of ra.x and ra.y are (which is not shown in the question).

Please remove const from the parameter "const RAngle& ra". You cannot modify a constant reference from a method.

Related

c++: compilation errors with std::endl and operator>>

I was writing a simple piece of c++ code to print out input till the input is not 42. Here is my code:
#include <iostream>
using namespace std;
int main(){
while(true){
int inp;
cin >> inp >> endl;
if(inp == 42){
break;
}
cout << inp << endl;
}
return 0;
}
However when I compile it ,I get a list of errors:
testlife.cpp: In function ‘int main()’:
testlife.cpp:9:14: error: no match for ‘operator>>’ (operand types are ‘std::basic_istream<char>::__istream_type {aka std::basic_istream<char>}’ and ‘<unresolved overloaded function type>’)
cin >> inp >> endl;
~~~~~~~~~~~^~~~~~~
In file included from /usr/include/c++/6/iostream:40:0,
from testlife.cpp:2:
/usr/include/c++/6/istream:120:7: note: candidate: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__istream_type& (*)(std::basic_istream<_CharT, _Traits>::__istream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
operator>>(__istream_type& (*__pf)(__istream_type&))
^~~~~~~~
/usr/include/c++/6/istream:120:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&) {aka std::basic_istream<char>& (*)(std::basic_istream<char>&)}’
/usr/include/c++/6/istream:124:7: note: candidate: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__ios_type& (*)(std::basic_istream<_CharT, _Traits>::__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>; std::basic_istream<_CharT, _Traits>::__ios_type = std::basic_ios<char>]
operator>>(__ios_type& (*__pf)(__ios_type&))
^~~~~~~~
/usr/include/c++/6/istream:124:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&) {aka std::basic_ios<char>& (*)(std::basic_ios<char>&)}’
/usr/include/c++/6/istream:131:7: note: candidate: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::ios_base& (*)(std::ios_base&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
operator>>(ios_base& (*__pf)(ios_base&))
^~~~~~~~
/usr/include/c++/6/istream:131:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘std::ios_base& (*)(std::ios_base&)’
/usr/include/c++/6/istream:168:7: note: candidate: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
operator>>(bool& __n)
^~~~~~~~
/usr/include/c++/6/istream:168:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘bool&’
/usr/include/c++/6/istream:172:7: note: candidate: std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char; _Traits = std::char_traits<char>]
operator>>(short& __n);
^~~~~~~~
/usr/include/c++/6/istream:172:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘short int&’
/usr/include/c++/6/istream:175:7: note: candidate: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(short unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
operator>>(unsigned short& __n)
^~~~~~~~
/usr/include/c++/6/istream:175:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘short unsigned int&’
/usr/include/c++/6/istream:179:7: note: candidate: std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char; _Traits = std::char_traits<char>]
operator>>(int& __n);
^~~~~~~~
/usr/include/c++/6/istream:179:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘int&’
/usr/include/c++/6/istream:182:7: note: candidate: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
operator>>(unsigned int& __n)
^~~~~~~~
/usr/include/c++/6/istream:182:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘unsigned int&’
/usr/include/c++/6/istream:186:7: note: candidate: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
operator>>(long& __n)
^~~~~~~~
/usr/include/c++/6/istream:186:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘long int&’
/usr/include/c++/6/istream:190:7: note: candidate: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
operator>>(unsigned long& __n)
^~~~~~~~
/usr/include/c++/6/istream:190:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘long unsigned int&’
/usr/include/c++/6/istream:195:7: note: candidate: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
operator>>(long long& __n)
^~~~~~~~
/usr/include/c++/6/istream:195:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘long long int&’
/usr/include/c++/6/istream:199:7: note: candidate: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
operator>>(unsigned long long& __n)
^~~~~~~~
/usr/include/c++/6/istream:199:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘long long unsigned int&’
/usr/include/c++/6/istream:214:7: note: candidate: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(float&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
operator>>(float& __f)
^~~~~~~~
/usr/include/c++/6/istream:214:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘float&’
/usr/include/c++/6/istream:218:7: note: candidate: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(double&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
operator>>(double& __f)
^~~~~~~~
/usr/include/c++/6/istream:218:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘double&’
/usr/include/c++/6/istream:222:7: note: candidate: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long double&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
operator>>(long double& __f)
^~~~~~~~
/usr/include/c++/6/istream:222:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘long double&’
/usr/include/c++/6/istream:235:7: note: candidate: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(void*&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
operator>>(void*& __p)
^~~~~~~~
/usr/include/c++/6/istream:235:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘void*&’
/usr/include/c++/6/istream:259:7: note: candidate: std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__streambuf_type*) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__streambuf_type = std::basic_streambuf<char>]
operator>>(__streambuf_type* __sb);
^~~~~~~~
/usr/include/c++/6/istream:259:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘std::basic_istream<char>::__streambuf_type* {aka std::basic_streambuf<char>*}’
In file included from /usr/include/c++/6/string:53:0,
from /usr/include/c++/6/bits/locale_classes.h:40,
from /usr/include/c++/6/bits/ios_base.h:41,
from /usr/include/c++/6/ios:42,
from /usr/include/c++/6/ostream:38,
from /usr/include/c++/6/iostream:39,
from testlife.cpp:2:
/usr/include/c++/6/bits/basic_string.tcc:1437:5: note: candidate: template<class _CharT, class _Traits, class _Alloc> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)
operator>>(basic_istream<_CharT, _Traits>& __in,
^~~~~~~~
/usr/include/c++/6/bits/basic_string.tcc:1437:5: note: template argument deduction/substitution failed:
testlife.cpp:9:17: note: couldn't deduce template parameter ‘_Alloc’
cin >> inp >> endl;
^~~~
In file included from /usr/include/c++/6/iostream:40:0,
from testlife.cpp:2:
/usr/include/c++/6/istream:799:5: note: candidate: std::basic_istream<_CharT2, _Traits2>& std::operator>>(std::basic_istream<_CharT2, _Traits2>&, _CharT2*) [with _CharT2 = char; _Traits2 = std::char_traits<char>; _CharT = char; _Traits = std::char_traits<char>]
operator>>(basic_istream<char>& __in, char* __s);
^~~~~~~~
/usr/include/c++/6/istream:799:5: note: no known conversion for argument 2 from ‘<unresolved overloaded function type>’ to ‘char*’
In file included from /usr/include/c++/6/istream:934:0,
from /usr/include/c++/6/iostream:40,
from testlife.cpp:2:
/usr/include/c++/6/bits/istream.tcc:923:5: note: candidate: std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, _CharT&) [with _CharT = char; _Traits = std::char_traits<char>]
operator>>(basic_istream<_CharT, _Traits>& __in, _CharT& __c)
^~~~~~~~
/usr/include/c++/6/bits/istream.tcc:923:5: note: no known conversion for argument 2 from ‘<unresolved overloaded function type>’ to ‘char&’
In file included from /usr/include/c++/6/iostream:40:0,
from testlife.cpp:2:
/usr/include/c++/6/istream:756:5: note: candidate: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, unsigned char&)
operator>>(basic_istream<char, _Traits>& __in, unsigned char& __c)
^~~~~~~~
/usr/include/c++/6/istream:756:5: note: template argument deduction/substitution failed:
testlife.cpp:9:17: note: cannot convert ‘std::endl’ (type ‘<unresolved overloaded function type>’) to type ‘unsigned char&’
cin >> inp >> endl;
^~~~
In file included from /usr/include/c++/6/iostream:40:0,
from testlife.cpp:2:
/usr/include/c++/6/istream:761:5: note: candidate: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, signed char&)
operator>>(basic_istream<char, _Traits>& __in, signed char& __c)
^~~~~~~~
/usr/include/c++/6/istream:761:5: note: template argument deduction/substitution failed:
testlife.cpp:9:17: note: cannot convert ‘std::endl’ (type ‘<unresolved overloaded function type>’) to type ‘signed char&’
cin >> inp >> endl;
^~~~
In file included from /usr/include/c++/6/iostream:40:0,
from testlife.cpp:2:
/usr/include/c++/6/istream:803:5: note: candidate: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, unsigned char*)
operator>>(basic_istream<char, _Traits>& __in, unsigned char* __s)
^~~~~~~~
/usr/include/c++/6/istream:803:5: note: template argument deduction/substitution failed:
testlife.cpp:9:17: note: cannot convert ‘std::endl’ (type ‘<unresolved overloaded function type>’) to type ‘unsigned char*’
cin >> inp >> endl;
^~~~
In file included from /usr/include/c++/6/iostream:40:0,
from testlife.cpp:2:
/usr/include/c++/6/istream:808:5: note: candidate: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, signed char*)
operator>>(basic_istream<char, _Traits>& __in, signed char* __s)
^~~~~~~~
/usr/include/c++/6/istream:808:5: note: template argument deduction/substitution failed:
testlife.cpp:9:17: note: cannot convert ‘std::endl’ (type ‘<unresolved overloaded function type>’) to type ‘signed char*’
cin >> inp >> endl;
^~~~
In file included from /usr/include/c++/6/iostream:40:0,
from testlife.cpp:2:
/usr/include/c++/6/istream:924:5: note: candidate: template<class _CharT, class _Traits, class _Tp> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&&, _Tp&)
operator>>(basic_istream<_CharT, _Traits>&& __is, _Tp& __x)
^~~~~~~~
/usr/include/c++/6/istream:924:5: note: template argument deduction/substitution failed:
testlife.cpp:9:17: note: couldn't deduce template parameter ‘_Tp’
cin >> inp >> endl;
I have never encountered such error before nor I am unable to debug it given the simple block of code I am writing. I am using g++ compiler installed on ubuntu system.
Remove the endl from the cin statement:
cin >> inp;
Instead of:
cin >> inp >> endl;
There's no overload of the std::endl I/O manipulator for std::istream as the error message clearly states.
Also you should handle errors when taking input, otherwise your loop will run forever:
int main(){
while(true){
int inp;
if(cin >> inp && inp == 42) {
break;
}
else {
cin.clear();
cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
continue;
}
cout << inp << endl;
}
return 0;
}

Create file and write to, filename is user input?

So I came on here earlier asking about a school assignment that involved reading each character from a file. That issue was fixed, but now I have encountered another problem.
Part of my assignment is to take in a user inputted file name, then set that file name to a text file that will be outputted with the results of the program.
Here is the program itself:
#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <fstream>
using namespace std;
int main()
{
const int fileNameSize = 20;
int fileCount = 0;
int testcount = 0;
const string outName;
std::ifstream inFile;
std::ofstream outFile;
<a bunch of other stuff>
outFile.open(outName);
int chartotal = acount + tcount + ecount + ocount + icount + ncount + scount + hcount + rcount;
outFile << "File name: " << inputFileName << endl;
outFile << "Number of E's: " << ecount << endl;
outFile << "Number of T's: " << tcount << endl;
outFile << "Number of A's: " << acount << endl;
outFile << "Number of O's: " << ocount << endl;
outFile << "Number of I's: " << icount << endl;
outFile << "Number of N's: " << ncount << endl;
outFile << "Number of S's: " << scount << endl;
outFile << "Number of H's: " << hcount << endl;
outFile << "Number of R's: " << rcount << endl;
outFile << "Total Number of Characters: " << chartotal << endl;
outFile << "--------------------------------" << endl;
outFile.close();
return 0;
}
inFile.close();
inFile.clear();
}
//cout << "exit colm flag";
//cout << "exit row flag\n";
}
It's my understanding that outFile.open(outName); should create a new file with the file name set as outName, however I just get a huge long error whenever I compile.
What am I doing wrong?
Edit: Here is the error I recieve
closed4Ahrens.cpp: In function 'int main()':
closed4Ahrens.cpp:19:9: error: no match for 'operator>>' in 'std::cin >> outName'
closed4Ahrens.cpp:19:9: note: candidates are:
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:122:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__istream_type& (*)(std::basic_istream<_CharT, _Traits>::__istream_type&)) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:122:7: note: no known conversion for argument 1 from 'const string {aka const std::basic_string<char>}' to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&) {aka std::basic_istream<char>& (*)(std::basic_istream<char>&)}'
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:126:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__ios_type& (*)(std::basic_istream<_CharT, _Traits>::__ios_type&)) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>, std::basic_istream<_CharT, _Traits>::__ios_type = std::basic_ios<char>]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:126:7: note: no known conversion for argument 1 from 'const string {aka const std::basic_string<char>}' to 'std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&) {aka std::basic_ios<char>& (*)(std::basic_ios<char>&)}'
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:133:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::ios_base& (*)(std::ios_base&)) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:133:7: note: no known conversion for argument 1 from 'const string {aka const std::basic_string<char>}' to 'std::ios_base& (*)(std::ios_base&)'
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:169:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:169:7: note: no known conversion for argument 1 from 'const string {aka const std::basic_string<char>}' to 'bool&'
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:173:7: note: std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char, _Traits = std::char_traits<char>]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:173:7: note: no known conversion for argument 1 from 'const string {aka const std::basic_string<char>}' to 'short int&'
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:176:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(short unsigned int&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:176:7: note: no known conversion for argument 1 from 'const string {aka const std::basic_string<char>}' to 'short unsigned int&'
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:180:7: note: std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char, _Traits = std::char_traits<char>]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:180:7: note: no known conversion for argument 1 from 'const string {aka const std::basic_string<char>}' to 'int&'
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:183:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(unsigned int&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:183:7: note: no known conversion for argument 1 from 'const string {aka const std::basic_string<char>}' to 'unsigned int&'
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:187:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long int&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:187:7: note: no known conversion for argument 1 from 'const string {aka const std::basic_string<char>}' to 'long int&'
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:191:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long unsigned int&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:191:7: note: no known conversion for argument 1 from 'const string {aka const std::basic_string<char>}' to 'long unsigned int&'
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:196:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long int&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:196:7: note: no known conversion for argument 1 from 'const string {aka const std::basic_string<char>}' to 'long long int&'
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:200:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long unsigned int&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:200:7: note: no known conversion for argument 1 from 'const string {aka const std::basic_string<char>}' to 'long long unsigned int&'
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:205:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(float&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:205:7: note: no known conversion for argument 1 from 'const string {aka const std::basic_string<char>}' to 'float&'
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:209:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(double&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:209:7: note: no known conversion for argument 1 from 'const string {aka const std::basic_string<char>}' to 'double&'
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:213:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long double&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:213:7: note: no known conversion for argument 1 from 'const string {aka const std::basic_string<char>}' to 'long double&'
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:217:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(void*&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:217:7: note: no known conversion for argument 1 from 'const string {aka const std::basic_string<char>}' to 'void*&'
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:241:7: note: std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__streambuf_type*) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__streambuf_type = std::basic_streambuf<char>]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:241:7: note: no known conversion for argument 1 from 'const string {aka const std::basic_string<char>}' to 'std::basic_istream<char>::__streambuf_type* {aka std::basic_streambuf<char>*}'
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/bits/basic_string.tcc:998:5: note: template<class _CharT, class _Traits, class _Alloc> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::basic_string<_CharT, _Traits, _Alloc>&)
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/bits/istream.tcc:957:5: note: template<class _CharT2, class _Traits2> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, _CharT2*)
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/bits/istream.tcc:925:5: note: template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, _CharT&)
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:709:5: note: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, unsigned char&)
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:714:5: note: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, signed char&)
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:756:5: note: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, unsigned char*)
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/istream:761:5: note: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, signed char*)
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/iomanip:70:5: note: template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Resetiosflags)
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/iomanip:100:5: note: template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Setiosflags)
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/iomanip:131:5: note: template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Setbase)
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/iomanip:169:5: note: template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Setfill<_CharT>)
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/iomanip:199:5: note: template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Setprecision)
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/iomanip:229:5: note: template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Setw)
closed4Ahrens.cpp:68:24: error: no matching function for call to 'std::basic_ofstream<char>::open(const string&)'
closed4Ahrens.cpp:68:24: note: candidate is:
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/fstream:702:7: note: void std::basic_ofstream<_CharT, _Traits>::open(const char*, std::ios_base::openmode) [with _CharT = char, _Traits = std::char_traits<char>, std::ios_base::openmode = std::_Ios_Openmode]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/fstream:702:7: note: no known conversion for argument 1 from 'const string {aka const std::basic_string<char>}' to 'const char*'
Update: I deleted the const in const string outName, now the error message is much shorter
closed4Ahrens.cpp:68:24: error: no matching function for call to 'std::basic_ofstream<char>::open(std::string&)'
closed4Ahrens.cpp:68:24: note: candidate is:
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/fstream:702:7: note: void std::basic_ofstream<_CharT, _Traits>::open(const char*, std::ios_base::openmode) [with _CharT = char, _Traits = std::char_traits<char>, std::ios_base::openmode = std::_Ios_Openmode]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/fstream:702:7: note: no known conversion for argument 1 from 'std::string {aka std::basic_string<char>}' to 'const char*'
Update 2: I've done as Paul Evans suggested
string outFileName;
ifstream inFile;
ofstream outFile;
char inputFileName [fileNameSize+1];
cout << "How many files are being processed?\n";
cin >> fileCount;
cout << "What is the output file name?\n";
cin >> outFileName;
const string outName(outFileName);
and
outFile.open(outName);
And now I am receiving this error message:
closed4Ahrens.cpp: In function 'int main()':
closed4Ahrens.cpp:70:17: error: no matching function for call to 'std::basic_ofstream<char>::open()'
closed4Ahrens.cpp:70:17: note: candidate is:
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/fstream:702:7: note: void std::basic_ofstream<_CharT, _Traits>::open(const char*, std::ios_base::openmode) [with _CharT = char, _Traits = std::char_traits<char>, std::ios_base::openmode = std::_Ios_Openmode]
/opt/csw/lib/gcc/i386-pc-solaris2.10/4.6.3/../../../../include/c++/4.6.3/fstream:702:7: note: candidate expects 2 arguments, 0 provided
Your telling the compiler that outfile is const without initializing it, don't do that. Do this instead:
const string outName{"The path of the outfile"};
or
string outFileName;
// get outFileName
const string outName{outFileName};

Convert string to __uint128_t using stringstreams

I'm trying to extract different types of data from a string.
void readHeader(char buf[BUFFSIZE])
{
std::istringstream hdr(buf);
__uint128_t id_client;
hdr >> id_client; // doesn't compile
}
I'm getting this error when I do that hdr >> id_client :
Unix/UnixSocket.cpp:158:10: error: ambiguous overload for ‘operator>>’ in ‘hdr >> id_client’ Unix/UnixSocket.cpp:158:10: note: candidates are: In file included from /usr/include/c++/4.7/sstream:39:0,
from Unix/UnixSocket.cpp:11: /usr/include/c++/4.7/istream:118:7: note: std::basic_istream<_CharT,
_Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__istream_type& (*)(std::basic_istream<_CharT, _Traits>::__istream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT,
_Traits>::__istream_type = std::basic_istream<char>] <near match> /usr/include/c++/4.7/istream:118:7: note: no known conversion for argument 1 from ‘__int128 unsigned’ to ‘std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&) {aka std::basic_istream<char>& (*)(std::basic_istream<char>&)}’ /usr/include/c++/4.7/istream:122:7: note: std::basic_istream<_CharT,
_Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__ios_type& (*)(std::basic_istream<_CharT, _Traits>::__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT,
_Traits>::__istream_type = std::basic_istream<char>; std::basic_istream<_CharT, _Traits>::__ios_type = std::basic_ios<char>] <near match> /usr/include/c++/4.7/istream:122:7:
Is there any way to properly store my id_client in this __uint128_t variable ?
https://gmplib.org/ might help. The mpz_class class of the gmpxx object abstraction supports I/O operators and the mpz_export(...) function allows you to transform the result into an array of bytes. If they exceed 16 bytes you may throw an exception or complain otherwise. Not very fast but I guess fast to implement.

I am getting an error in the following program, and I am not sure what is to be done [closed]

Closed. This question is not reproducible or was caused by typos. It is not currently accepting answers.
This question was caused by a typo or a problem that can no longer be reproduced. While similar questions may be on-topic here, this one was resolved in a way less likely to help future readers.
Closed 8 years ago.
Improve this question
The code is given as follows:
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
using namespace std;
inline void keep_window_open() { char ch; cin >> ch; }
int main()
{
string operation;
double num1, num2, val;
cout << "Enter the operation followed by the numbers\n";
cin >> operation >> num1 >> num2 >> endl;
if (operation == "+") {
cout << operation << num1 << num2 << endl;
val = num1 + num2;
cout << val << endl;
}
if (operation == "-") {
cout << operation << num1 << num2 << endl;
val = num1 - num2;
cout << val << endl;
}
if (operation == "*") {
cout << operation << num1 << num2 << endl;
val = num1 * num2;
cout << val << endl;
}
if (operation == "/") {
cout << operation << num1 << num2 << endl;
val = num1 / num2;
cout << val << endl;
}
}
I am getting the following error:
operands.cpp: In function ‘int main()’:
operands.cpp:13:39: error: no match for ‘operator>>’ in ‘(&(& std::operator>> [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>]((* & std::cin), (* & operation)))->std::basic_istream<_CharT, _Traits>::operator>> [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]((* & num1)))->std::basic_istream<_CharT, _Traits>::operator>> [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]((* & num2)) >> std::endl’
operands.cpp:13:39: note: candidates are:
/usr/include/c++/4.6/istream:122:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__istream_type& (*)(std::basic_istream<_CharT, _Traits>::__istream_type&)) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:122:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&) {aka std::basic_istream<char>& (*)(std::basic_istream<char>&)}’
/usr/include/c++/4.6/istream:126:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__ios_type& (*)(std::basic_istream<_CharT, _Traits>::__ios_type&)) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>, std::basic_istream<_CharT, _Traits>::__ios_type = std::basic_ios<char>]
/usr/include/c++/4.6/istream:126:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&) {aka std::basic_ios<char>& (*)(std::basic_ios<char>&)}’
/usr/include/c++/4.6/istream:133:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::ios_base& (*)(std::ios_base&)) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:133:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘std::ios_base& (*)(std::ios_base&)’
/usr/include/c++/4.6/istream:169:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:169:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘bool&’
/usr/include/c++/4.6/istream:173:7: note: std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/include/c++/4.6/istream:173:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘short int&’
/usr/include/c++/4.6/istream:176:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(short unsigned int&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:176:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘short unsigned int&’
/usr/include/c++/4.6/istream:180:7: note: std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/include/c++/4.6/istream:180:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘int&’
/usr/include/c++/4.6/istream:183:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(unsigned int&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:183:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘unsigned int&’
/usr/include/c++/4.6/istream:187:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long int&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:187:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘long int&’
/usr/include/c++/4.6/istream:191:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long unsigned int&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:191:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘long unsigned int&’
/usr/include/c++/4.6/istream:196:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long int&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:196:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘long long int&’
/usr/include/c++/4.6/istream:200:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long unsigned int&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:200:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘long long unsigned int&’
/usr/include/c++/4.6/istream:205:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(float&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:205:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘float&’
/usr/include/c++/4.6/istream:209:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(double&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:209:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘double&’
/usr/include/c++/4.6/istream:213:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long double&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:213:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘long double&’
/usr/include/c++/4.6/istream:217:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(void*&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:217:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘void*&’
/usr/include/c++/4.6/istream:241:7: note: std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__streambuf_type*) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__streambuf_type = std::basic_streambuf<char>]
/usr/include/c++/4.6/istream:241:7: note: no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘std::basic_istream<char>::__streambuf_type* {aka std::basic_streambuf<char>*}’
/usr/include/c++/4.6/bits/basic_string.tcc:998:5: note: template<class _CharT, class _Traits, class _Alloc> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::basic_string<_CharT, _Traits, _Alloc>&)
/usr/include/c++/4.6/istream:752:5: note: std::basic_istream<_CharT2, _Traits2>& std::operator>>(std::basic_istream<_CharT2, _Traits2>&, _CharT2*) [with _CharT2 = char, _Traits2 = std::char_traits<char>, _CharT = char, _Traits = std::char_traits<char>]
/usr/include/c++/4.6/istream:752:5: note: no known conversion for argument 2 from ‘<unresolved overloaded function type>’ to ‘char*’
/usr/include/c++/4.6/bits/istream.tcc:925:5: note: std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, _CharT&) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/include/c++/4.6/bits/istream.tcc:925:5: note: no known conversion for argument 2 from ‘<unresolved overloaded function type>’ to ‘char&’
/usr/include/c++/4.6/istream:709:5: note: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, unsigned char&)
/usr/include/c++/4.6/istream:714:5: note: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, signed char&)
/usr/include/c++/4.6/istream:756:5: note: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, unsigned char*)
/usr/include/c++/4.6/istream:761:5: note: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, signed char*)
Don't put >> endl after cin ! That is, replace
cin >> operation >> num1 >> num2 >> endl;
with
cin >> operation >> num1 >> num2;

C++ Ambiguous overload in operator>> for complex class

I am constantly getting an ambiguous overload error no matter what I do ....
here's my code
COMPLEX.cpp code
template<class C> class complex
{
C real,imag;
public:
//constructors
complex(C real=0,C imag=0)
{
complex::real=real;
complex::imag=imag;
}
complex(const complex& cmplx)
{
real=cmplx.real;
imag=cmplx.imag;
}
//functions available
complex<C> operator+(const complex&);
complex<C> operator+(double);
void operator=(const complex&);
//friend functions available
template<class F> friend complex<F> operator+(double,const complex<F>&);
template<class F> friend istream& operator>>(istream&,const complex<F>&);
template<class F> friend ostream& operator<<(ostream&,const complex<F>&);
};
OPERATOR>> implementation
template<class F> istream& operator>>(istream& cin,const complex<F>& cmplx)
{
cout<<"\nenter real part followed by imaginary part : ";
cin>>cmplx.real>>cmplx.imag;
return cin;
}
MAIN method
int main(void)
{
complex<int> C1;
complex<int> C2;
complex<int> C3;
cin>>C1>>C2>>C3;
cout<<C1<<C2<<C3;
C1=C1+3;
C2=2+C2;
C3=C1+C2;
cout<<C1<<C2<<C3;
complex<int> C4(C3);
cout<<C4;
return 0;
}
COMPILER ERROR
COMPLEX.cpp: In function ‘std::istream& operator>>(std::istream&, const complex<C>&) [with F = int, std::istream = std::basic_istream<char>]’:
COMPLEX.cpp:91:7: instantiated from here
COMPLEX.cpp:75:2: error: ambiguous overload for ‘operator>>’ in ‘cin >> cmplx.complex<int>::real’
COMPLEX.cpp:75:2: note: candidates are:
/usr/include/c++/4.6/istream:122:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__istream_type& (*)(std::basic_istream<_CharT, _Traits>::__istream_type&)) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>] <near match>
/usr/include/c++/4.6/istream:122:7: note: no known conversion for argument 1 from ‘const int’ to ‘std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&) {aka std::basic_istream<char>& (*)(std::basic_istream<char>&)}’
/usr/include/c++/4.6/istream:126:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__ios_type& (*)(std::basic_istream<_CharT, _Traits>::__ios_type&)) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>, std::basic_istream<_CharT, _Traits>::__ios_type = std::basic_ios<char>] <near match>
/usr/include/c++/4.6/istream:126:7: note: no known conversion for argument 1 from ‘const int’ to ‘std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&) {aka std::basic_ios<char>& (*)(std::basic_ios<char>&)}’
/usr/include/c++/4.6/istream:133:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::ios_base& (*)(std::ios_base&)) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>] <near match>
/usr/include/c++/4.6/istream:133:7: note: no known conversion for argument 1 from ‘const int’ to ‘std::ios_base& (*)(std::ios_base&)’
/usr/include/c++/4.6/istream:241:7: note: std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__streambuf_type*) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__streambuf_type = std::basic_streambuf<char>] <near match>
/usr/include/c++/4.6/istream:241:7: note: no known conversion for argument 1 from ‘const int’ to ‘std::basic_istream<char>::__streambuf_type* {aka std::basic_streambuf<char>*}’
before this I wrote a MATRIX.cpp and istream overload works fine there even though its nearly the same as here....
template<class F> istream& operator>>(istream& cin,const complex<F>& cmplx)
^^^^^
That const is a problem - you need to change cmplx here, it can't be const. That's what the compiler is complaining about: cmplx.real is const int inside that function.