https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99749
Bug ID: 99749
Summary: Error when using std::string in a module (versions
11.0.1 20210307, 11.0.1 20210314, and 11.0.1 20210321)
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: patrick.kox at commandoregel dot be
Target Milestone: ---
Created attachment 50468
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50468&action=edit
AirlineTicket example code from Professional C++ 5th Edition
When trying to compile the "AirlineTicket" example/exercise from the book
Professional C++ (5th edition by Marc Gregoire) I'm getting the following error
message when I use a std::string in my module.
The complete error is:
---------------------
In file included from /opt/gcc-11/include/c++/11.0.1/string:55,
of module /opt/gcc-11/include/c++/11.0.1/string, imported at
AirlineTicket.cpp:3,
of module airline_ticket, imported at main.cpp:2:
/opt/gcc-11/include/c++/11.0.1/bits/basic_string.h: In function ‘int main()’:
/opt/gcc-11/include/c++/11.0.1/bits/basic_string.h:431:7: error:
‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string() [with
_CharT = char; _Traits = std::char_traits<char>; _Alloc =
std::allocator<char>]’ cannot be overloaded with
‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string() [with
_CharT = char; _Traits = std::char_traits<char>; _Alloc =
std::allocator<char>]’
431 | basic_string()
| ^~~~~~~~~~~~
In file included from /opt/gcc-11/include/c++/11.0.1/string:55,
from /opt/gcc-11/include/c++/11.0.1/bits/locale_classes.h:40,
from /opt/gcc-11/include/c++/11.0.1/bits/ios_base.h:41,
from /opt/gcc-11/include/c++/11.0.1/ios:42,
from /opt/gcc-11/include/c++/11.0.1/ostream:38,
from /opt/gcc-11/include/c++/11.0.1/iostream:39,
of module /opt/gcc-11/include/c++/11.0.1/iostream, imported at main.cpp:1:
/opt/gcc-11/include/c++/11.0.1/bits/basic_string.h:431:7: note: previous
declaration ‘std::__cxx11::basic_string<_CharT, _Traits,
_Alloc>::basic_string() [with _CharT = char; _Traits = std::char_traits<char>;
_Alloc = std::allocator<char>]’
431 | basic_string()
| ^~~~~~~~~~~~
In file included from /opt/gcc-11/include/c++/11.0.1/string:55,
of module /opt/gcc-11/include/c++/11.0.1/string, imported at
AirlineTicket.cpp:3,
of module airline_ticket, imported at main.cpp:2:
/opt/gcc-11/include/c++/11.0.1/bits/basic_string.h:431:7: error:
‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string() [with
_CharT = char; _Traits = std::char_traits<char>; _Alloc =
std::allocator<char>]’ cannot be overloaded with
‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string() [with
_CharT = char; _Traits = std::char_traits<char>; _Alloc =
std::allocator<char>]’
431 | basic_string()
| ^~~~~~~~~~~~
In file included from /opt/gcc-11/include/c++/11.0.1/string:55,
from /opt/gcc-11/include/c++/11.0.1/bits/locale_classes.h:40,
from /opt/gcc-11/include/c++/11.0.1/bits/ios_base.h:41,
from /opt/gcc-11/include/c++/11.0.1/ios:42,
from /opt/gcc-11/include/c++/11.0.1/ostream:38,
from /opt/gcc-11/include/c++/11.0.1/iostream:39,
of module /opt/gcc-11/include/c++/11.0.1/iostream, imported at main.cpp:1:
/opt/gcc-11/include/c++/11.0.1/bits/basic_string.h:431:7: note: previous
declaration ‘std::__cxx11::basic_string<_CharT, _Traits,
_Alloc>::basic_string() [with _CharT = char; _Traits = std::char_traits<char>;
_Alloc = std::allocator<char>]’
431 | basic_string()
| ^~~~~~~~~~~~
main.cpp:6:9: note: during load of binding ‘::AirlineTicket@airline_ticket’
6 | AirlineTicket myTicket;
| ^~~~~~~~~~~~~
make: *** [Makefile:76: debug] Error 1
---------------------
The code that I'm using is:
---------------------
export module airline_ticket;
import<string>;
export class AirlineTicket{
public:
AirlineTicket();
~AirlineTicket();
double calculatePriceInDollars()const;
std::string getPassengerName()const;
void setPassengerName(std::string name);
int getNumberOfMiles() const;
void setNumberOfMiles(int miles);
bool hasEliteSuperRewardsStatus() const;
void setHasEliteSuperRecardsStatus(bool status);
private:
std::string m_passengerName{};
int m_numberOfMiles{};
bool m_hasEliteSuperRewardsStatus{};
};
AirlineTicket::AirlineTicket() : m_passengerName{"Unknown Passenger"},
m_numberOfMiles{0},m_hasEliteSuperRewardsStatus{false}{}
AirlineTicket::~AirlineTicket() {}
double AirlineTicket::calculatePriceInDollars() const
{
if (hasEliteSuperRewardsStatus()) {
// Elite Super Rewards Customers fly for free.
return 0;
}
// The cost of a ticket is the number of miles times 0.1.
// Real airlines probably have a more complicated
// formula!
return getNumberOfMiles() * 0.1;
}
std::string AirlineTicket::getPassengerName()const {
return m_passengerName;
}
void AirlineTicket::setPassengerName(std::string name)
{
m_passengerName = name;
}
void AirlineTicket::setPassengerInitial(char initial)
{
m_passengerInitial = initial;
}
int AirlineTicket::getNumberOfMiles() const
{
return m_numberOfMiles;
}
void AirlineTicket::setNumberOfMiles(int miles)
{
m_numberOfMiles = miles;
}
bool AirlineTicket::hasEliteSuperRewardsStatus() const
{
return m_hasEliteSuperRewardsStatus;
}
void AirlineTicket::setHasEliteSuperRecardsStatus(bool status)
{
m_hasEliteSuperRewardsStatus = status;
}
---------------------
When I remove the string from the code, it compiles without problem, also when
I use a string in main() there is no error.
Also the following 2 compile commands run without problem:
g++ -Wall -Wextra -fmodules-ts -std=gnu++20 -pedantic -c -x c++-system-header
iostream string
and
g++ -Wall -Wextra -fmodules-ts -std=gnu++20 -pedantic -c AirlineTicket.cpp
I've attached a tarball with the AirlineTicket.cpp and main.cpp files
